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X-Ray Photons in the CO 2-1 Lacuna of NGC 2110Fabbiano, GiuseppinaPaggi, A.Elvis, Martin2019DOI: info:10.3847/2041-8213/ab1c63The Astrophysical Journalv. 876 L18 L180004-637X
Fabbiano, Giuseppina, Paggi, A., and Elvis, Martin. 2019. "X-Ray Photons in the CO 2-1 "Lacuna" of NGC 2110." The Astrophysical Journal 876: L18. https://doi.org/10.3847/2041-8213/ab1c63
ID: 155158
Type: article
Authors: Fabbiano, Giuseppina; Paggi, A.; Elvis, Martin
Keywords: SAO
Abstract: A recent Atacama Large Millimeter/submillimeter Array study of the Seyfert 2 active galactic nucleus (AGN) NGC 2110 by Rosario et al. has reported a remarkable lack of CO 2-1 emission from the circumnuclear region, where optical lines and H2 emission are observed, leading to the suggestion of excitation of the molecular clouds by the AGN. As interaction with X-ray photons could be the cause of this excitation, we have searched the archival Chandra data for corroborating evidence. We report the discovery of an extra-nuclear ∼1″ (∼170 pc) feature in the soft ( emission are observed, leading to the suggestion of excitation of the molecular clouds by the AGN. As interaction with X-ray photons could be the cause of this excitation, we have searched the archival Chandra data for corroborating evidence. We report the discovery of an extra-nuclear ∼1″ (∼170 pc) feature in the soft (2 emission in this region, which is devoid of CO 2-1 emission. The Chandra image completes the emerging picture of a multiphase circumnuclear medium excited by the X-rays from the AGN, with dense warm molecular clouds emitting in H2 but depleted of CO 2-1 line emission.
The 2005-2016 Trends of Formaldehyde Columns Over China Observed by Satellites: Increasing Anthropogenic Emissions of Volatile Organic Compounds and Decreasing Agricultural Fire EmissionsShen, LuJacob, Daniel J.Zhu, LeiZhang, QiangZheng, BoSulprizio, Melissa P.Li, KeDe Smedt, IsabelleGonzález Abad, GonzaloCao, HansenFu, Tzung-MayLiao, Hong2019DOI: info:10.1029/2019GL082172Geophysical Research Lettersv. 46 4468 44754468–44750094-8276
Shen, Lu, Jacob, Daniel J., Zhu, Lei, Zhang, Qiang, Zheng, Bo, Sulprizio, Melissa P., Li, Ke, De Smedt, Isabelle, González Abad, Gonzalo, Cao, Hansen, Fu, Tzung-May, and Liao, Hong. 2019. "The 2005-2016 Trends of Formaldehyde Columns Over China Observed by Satellites: Increasing Anthropogenic Emissions of Volatile Organic Compounds and Decreasing Agricultural Fire Emissions." Geophysical Research Letters 46: 4468– 4475. https://doi.org/10.1029/2019GL082172
ID: 155159
Type: article
Authors: Shen, Lu; Jacob, Daniel J.; Zhu, Lei; Zhang, Qiang; Zheng, Bo; Sulprizio, Melissa P.; Li, Ke; De Smedt, Isabelle; González Abad, Gonzalo; Cao, Hansen; Fu, Tzung-May; Liao, Hong
Keywords: SAO
Abstract: We use 2005-2016 observations of formaldehyde (HCHO) columns over China from the OMI, GOME-2, and SCIAMACHY satellite instruments to evaluate long-term trends in emission inventories of volatile organic compounds (VOCs) that affect air quality. The observations show large increases over 2005-2016 in the North China Plain (+1.1 ± 0.5% a-1 relative to 2005) and the Yangtze River Delta region (+1.5 ± 0.4% a-1 relative to 2005), consistent with the trend of anthropogenic VOC emissions in the Multi-resolution Emission Inventory for China (MEIC). Unlike other pollutants, VOC emissions have not been decreasing in recent years. An exception is the Huai River Basin in rural eastern China where the satellite data show rapidly decreasing VOC emissions since the early 2010s that appear to reflect bans on agricultural fires.
Radio observations of the merging galaxy cluster Abell 520 (Corrigendum)Hoang, D. N.Shimwell, T. W.van Weeren, R. J.Brunetti, G.Röttgering, Huub J. A.Andrade-Santos, F.Botteon, A.Brüggen, M.Cassano, R.Drabent, A.de Gasperin, F.Hoeft, M.Intema, H. T.Rafferty, D. A.Shweta, A.Stroe, A.2019DOI: info:10.1051/0004-6361/201833900eAstronomy and Astrophysicsv. 624 C1 C10004-6361
Hoang, D. N., Shimwell, T. W., van Weeren, R. J., Brunetti, G., Röttgering, Huub J. A., Andrade-Santos, F., Botteon, A., Brüggen, M., Cassano, R., Drabent, A., de Gasperin, F., Hoeft, M., Intema, H. T., Rafferty, D. A., Shweta, A., and Stroe, A. 2019. "Radio observations of the merging galaxy cluster Abell 520 (Corrigendum)." Astronomy and Astrophysics 624: C1. https://doi.org/10.1051/0004-6361/201833900e
ID: 155160
Type: article
Authors: Hoang, D. N.; Shimwell, T. W.; van Weeren, R. J.; Brunetti, G.; Röttgering, Huub J. A.; Andrade-Santos, F.; Botteon, A.; Brüggen, M.; Cassano, R.; Drabent, A.; de Gasperin, F.; Hoeft, M.; Intema, H. T.; Rafferty, D. A.; Shweta, A.; Stroe, A.
Keywords: SAO
Special Section Guest Editorial: Lynx X-Ray ObservatoryGaskin, JessicaÖzel, FeryalVikhlinin, AlexeySwartz, Douglas2019DOI: info:10.1117/1.JATIS.5.2.021000Journal of Astronomical Telescopes, Instruments, and Systemsv. 5 021000 0210002329-4124
Gaskin, Jessica, Özel, Feryal, Vikhlinin, Alexey, and Swartz, Douglas. 2019. "Special Section Guest Editorial: Lynx X-Ray Observatory." Journal of Astronomical Telescopes, Instruments, and Systems 5: 021000. https://doi.org/10.1117/1.JATIS.5.2.021000
ID: 155161
Type: article
Authors: Gaskin, Jessica; Özel, Feryal; Vikhlinin, Alexey; Swartz, Douglas
Keywords: SAO
Abstract: This guest editorial introduces the Special Section on the Lynx X-Ray Observatory.
Internal filament modulation in low-dielectric gap design for built-in selector-less resistive switching memory applicationChen, Ying-ChenLin, Chih-YangHuang, Hui-ChunKim, SungjunFowler, BurtChang, Yao-FengWu, XiaohanXu, GaoboChang, Ting-ChangLee, Jack C.2018DOI: info:10.1088/1361-6463/aaa1b9Journal of Physics D: Applied Physicsv. 51No. 5 055108 0551080022-3727
Chen, Ying-Chen, Lin, Chih-Yang, Huang, Hui-Chun, Kim, Sungjun, Fowler, Burt, Chang, Yao-Feng, Wu, Xiaohan, Xu, Gaobo, Chang, Ting-Chang, and Lee, Jack C. 2018. "Internal filament modulation in low-dielectric gap design for built-in selector-less resistive switching memory application." Journal of Physics D: Applied Physics 51 (5): 055108. https://doi.org/10.1088/1361-6463/aaa1b9
ID: 154760
Type: article
Authors: Chen, Ying-Chen; Lin, Chih-Yang; Huang, Hui-Chun; Kim, Sungjun; Fowler, Burt; Chang, Yao-Feng; Wu, Xiaohan; Xu, Gaobo; Chang, Ting-Chang; Lee, Jack C.
Keywords: SAO
Efficient variational approach to dynamics of a spatially extended bosonic Kondo modelAshida, YutoShi, TaoSchmidt, RichardSadeghpour, Hossein R.Cirac, J. IgnacioDemler, Eugene2019DOI: info:10.1103/PhysRevA.100.043618Physical Review Av. 100 043618 0436181050-2947
Ashida, Yuto, Shi, Tao, Schmidt, Richard, Sadeghpour, Hossein R., Cirac, J. Ignacio, and Demler, Eugene. 2019. "Efficient variational approach to dynamics of a spatially extended bosonic Kondo model." Physical Review A 100: 043618. https://doi.org/10.1103/PhysRevA.100.043618
ID: 154692
Type: article
Authors: Ashida, Yuto; Shi, Tao; Schmidt, Richard; Sadeghpour, Hossein R.; Cirac, J. Ignacio; Demler, Eugene
Keywords: SAO
Abstract: We develop an efficient variational approach to studying dynamics of a localized quantum spin coupled to a bath of mobile spinful bosons. We use parity symmetry to decouple the impurity spin from the environment via a canonical transformation and reduce the problem to a model of the interacting bosonic bath. We describe coherent time evolution of the latter using bosonic Gaussian states as a variational ansatz. We provide full analytical expressions for equations describing variational time evolution that can be applied to study in- and out-of-equilibrium phenomena in a wide class of quantum impurity problems. In the accompanying paper [Ashida et al., Phys. Rev. Lett. 123, 183001 (2019), 10.1103/PhysRevLett.123.183001], we present a concrete application of this general formalism to the analysis of the Rydberg central spin model, in which the spin-1/2 Rydberg impurity undergoes spin-changing collisions in a dense cloud of two-component ultracold bosons. To illustrate new features arising from orbital motion of the bath atoms, we compare our results to the Monte Carlo study of the model with spatially localized bosons in the bath, in which random positions of the atoms give rise to random couplings of the standard central spin model.
SuperWASP dispositions and false positive catalogueSchanche, N.Collier Cameron, A.Almenara, J. M.Alsubai, K. A.Anderson, D. R.Armstrong, D. J.Barkaoui, K.Barros, S. C. C.Bochiński, J.Bonomo, A. S.Bouchy, F.Brown, D. J. A.Burdanov, A.Busuttil, R.Deleuil, M.Delrez, L.Faedi, F.Gillon, M.Hay, K.Hebb, L.Hébrard, G.Jehin, E.Kolb, U.Maxted, P. F. L.Miller, G.Nielsen, L. D.Pollacco, D. L.Pozuelos, F. J.Queloz, D.Relles, HowardSmalley, B.Triaud, A. H. M. J.Udry, S.West, R.Wheatley, P. J.2019DOI: info:10.1093/mnras/stz2064Monthly Notices of the Royal Astronomical Societyv. 488 4905 49154905–49150035-8711
Schanche, N., Collier Cameron, A., Almenara, J. M., Alsubai, K. A., Anderson, D. R., Armstrong, D. J., Barkaoui, K., Barros, S. C. C., Bochiński, J., Bonomo, A. S., Bouchy, F., Brown, D. J. A., Burdanov, A., Busuttil, R., Deleuil, M., Delrez, L., Faedi, F., Gillon, M., Hay, K., Hebb, L., Hébrard, G., Jehin, E., Kolb, U., Maxted, P. F. L., Miller, G. et al. 2019. "SuperWASP dispositions and false positive catalogue." Monthly Notices of the Royal Astronomical Society 488: 4905– 4915. https://doi.org/10.1093/mnras/stz2064
ID: 154693
Type: article
Authors: Schanche, N.; Collier Cameron, A.; Almenara, J. M.; Alsubai, K. A.; Anderson, D. R.; Armstrong, D. J.; Barkaoui, K.; Barros, S. C. C.; Bochiński, J.; Bonomo, A. S.; Bouchy, F.; Brown, D. J. A.; Burdanov, A.; Busuttil, R.; Deleuil, M.; Delrez, L.; Faedi, F.; Gillon, M.; Hay, K.; Hebb, L.; Hébrard, G.; Jehin, E.; Kolb, U.; Maxted, P. F. L.; Miller, G.; Nielsen, L. D.; Pollacco, D. L.; Pozuelos, F. J.; Queloz, D.; Relles, Howard; Smalley, B.; Triaud, A. H. M. J.; Udry, S.; West, R.; Wheatley, P. J.
Keywords: SAO
Abstract: SuperWASP, the Northern hemisphere WASP observatory, has been observing the skies from La Palma since 2004. In that time, more than 50 planets have been discovered with data contributions from SuperWASP. In the process of validating planets, many false-positive candidates have also been identified. The TESS telescope is set to begin observations of the northern sky in 2019. Similar to the WASP survey, the TESS pixel size is relatively large (13 arcsec for WASP and 21 arcsec for TESS), making it susceptible to many blended signals and false detections caused principally by grazing and blended stellar eclipsing binary systems. In order to reduce duplication of effort on targets, we present a catalogue of 1 041 Northern hemisphere SuperWASP targets that have been rejected as planetary transits through follow-up observation.
Interpreting Crab Nebula's synchrotron spectrum: two acceleration mechanismsLyutikov, MaximTemim, TeaKomissarov, SergeySlane, PatrickSironi, LorenzoComisso, Luca2019DOI: info:10.1093/mnras/stz2023Monthly Notices of the Royal Astronomical Societyv. 489 2403 24162403–24160035-8711
Lyutikov, Maxim, Temim, Tea, Komissarov, Sergey, Slane, Patrick, Sironi, Lorenzo, and Comisso, Luca. 2019. "Interpreting Crab Nebula's synchrotron spectrum: two acceleration mechanisms." Monthly Notices of the Royal Astronomical Society 489: 2403– 2416. https://doi.org/10.1093/mnras/stz2023
ID: 154694
Type: article
Authors: Lyutikov, Maxim; Temim, Tea; Komissarov, Sergey; Slane, Patrick; Sironi, Lorenzo; Comisso, Luca
Keywords: SAO
Abstract: We outline a model of the Crab pulsar wind nebula with two different populations of synchrotron emitting particles, arising from two different acceleration mechanisms: (i) Component-I due to Fermi-I acceleration at the equatorial portion of the termination shock, with particle spectral index pI ≈ 2.2 above the injection break corresponding to γwindσwind ̃ 105, peaking in the ultraviolet (UV, γwind ̃ 102 is the bulk Lorentz factor of the wind, σwind ̃ 103 is wind magnetization); and (ii) Component-II due to acceleration at reconnection layers in the bulk of the turbulent Nebula, with particle index pII ≈ 1.6. The model requires relatively slow but highly magnetized wind. For both components, the overall cooling break is in the infrared at ̃0.01 eV, so that the Component-I is in the fast cooling regime (cooling frequency below the peak frequency). In the optical band, Component-I produces emission with the cooling spectral index of αo ≈ 0.5, softening towards the edges due to radiative losses. Above the cooling break, in the optical, UV, and X-rays, Component-I mostly overwhelms Component-II. We hypothesize that acceleration at large-scale current sheets in the turbulent nebula (Component-II) extends to the synchrotron burn-off limit of ∊s ̃ 100 MeV. Thus in our model acceleration in turbulent reconnection (Component-II) can produce both hard radio spectra and occasional gamma-ray flares. This model may be applicable to a broader class of high-energy astrophysical objects, like active galactic nuclei and gamma-ray burst jets, where often radio electrons form a different population from the high-energy electrons.
Runaway merger shocks in galaxy cluster outskirts and radio relicsZhang, CongyaoChurazov, EugeneForman, William R.Lyskova, Natalia2019DOI: info:10.1093/mnras/stz2135Monthly Notices of the Royal Astronomical Societyv. 488 5259 52665259–52660035-8711
Zhang, Congyao, Churazov, Eugene, Forman, William R., and Lyskova, Natalia. 2019. "Runaway merger shocks in galaxy cluster outskirts and radio relics." Monthly Notices of the Royal Astronomical Society 488: 5259– 5266. https://doi.org/10.1093/mnras/stz2135
ID: 154695
Type: article
Authors: Zhang, Congyao; Churazov, Eugene; Forman, William R.; Lyskova, Natalia
Keywords: SAO
Abstract: Moderately strong shocks arise naturally when two subclusters merge. For instance, when a smaller subcluster falls into the gravitational potential of a more massive cluster, a bow shock is formed and moves together with the subcluster. After pericentre passage, however, the subcluster is decelerated by the gravity of the main cluster, while the shock continues moving away from the cluster centre. These shocks are considered as promising candidates for powering radio relics found in many clusters. The aim of this paper is to explore the fate of such shocks when they travel to the cluster outskirts, far from the place where the shocks were initiated. In a uniform medium, such a `runaway' shock should weaken with distance. However, as shocks move to large radii in galaxy clusters, the shock is moving down a steep density gradient that helps the shock to maintain its strength over a large distance. Observations and numerical simulations show that, beyond R500, gas density profiles are as steep as, or steeper than, ̃r-3, suggesting that there exists a `habitable zone' for moderately strong shocks in cluster outskirts where the shock strength can be maintained or even amplified. A characteristic feature of runaway shocks is that the strong compression, relative to the initial state, is confined to a narrow region just behind the shock. Therefore, if such a shock runs over a region with a pre-existing population of relativistic particles, then the boost in radio emissivity, due to pure adiabatic compression, will also be confined to a narrow radial shell.
Deep ugrizY imaging and DEEP2/3 spectroscopy: a photometric redshift testbed for LSST and public release of data from the DEEP3 Galaxy Redshift SurveyZhou, RongpuCooper, Michael C.Newman, Jeffrey A.Ashby, Matthew L. N.Aird, JamesConselice, Christopher J.Davis, MarcDutton, Aaron A.Faber, S. M.Fang, Jerome J.Fazio, Giovanni G.Guhathakurta, PuragraKocevski, DaleKoo, David C.Nandra, KirpalPhillips, Andrew C.Rosario, David J.Schlafly, Edward F.Trump, Jonathan R.Weiner, BenjaminWillmer, Christopher N. A.Yan, Renbin2019DOI: info:10.1093/mnras/stz1866Monthly Notices of the Royal Astronomical Societyv. 488 4565 45844565–45840035-8711
Zhou, Rongpu, Cooper, Michael C., Newman, Jeffrey A., Ashby, Matthew L. N., Aird, James, Conselice, Christopher J., Davis, Marc, Dutton, Aaron A., Faber, S. M., Fang, Jerome J., Fazio, Giovanni G., Guhathakurta, Puragra, Kocevski, Dale, Koo, David C., Nandra, Kirpal, Phillips, Andrew C., Rosario, David J., Schlafly, Edward F., Trump, Jonathan R., Weiner, Benjamin, Willmer, Christopher N. A., and Yan, Renbin. 2019. "Deep ugrizY imaging and DEEP2/3 spectroscopy: a photometric redshift testbed for LSST and public release of data from the DEEP3 Galaxy Redshift Survey." Monthly Notices of the Royal Astronomical Society 488: 4565– 4584. https://doi.org/10.1093/mnras/stz1866
ID: 154696
Type: article
Authors: Zhou, Rongpu; Cooper, Michael C.; Newman, Jeffrey A.; Ashby, Matthew L. N.; Aird, James; Conselice, Christopher J.; Davis, Marc; Dutton, Aaron A.; Faber, S. M.; Fang, Jerome J.; Fazio, Giovanni G.; Guhathakurta, Puragra; Kocevski, Dale; Koo, David C.; Nandra, Kirpal; Phillips, Andrew C.; Rosario, David J.; Schlafly, Edward F.; Trump, Jonathan R.; Weiner, Benjamin; Willmer, Christopher N. A.; Yan, Renbin
Keywords: SAO
Abstract: We present catalogues of calibrated photometry and spectroscopic redshifts in the Extended Groth Strip, intended for studies of photometric redshifts (photo-z's). The data includes ugriz photometry from Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) and Y-band photometry from the Subaru Suprime camera, as well as spectroscopic redshifts from the DEEP2, DEEP3, and 3D-HST surveys. These catalogues incorporate corrections to produce effectively matched-aperture photometry across all bands, based upon object size information available in the catalogue and Moffat profile point spread function fits. We test this catalogue with a simple machine learning-based photometric redshift algorithm based upon Random Forest regression, and find that the corrected aperture photometry leads to significant improvement in photo-z accuracy compared to the original SEXTRACTOR catalogues from CFHTLS and Subaru. The deep ugrizY photometry and spectroscopic redshifts are well suited for empirical tests of photometric redshift algorithms for LSST. The resulting catalogues are publicly available at http://d-scholarship.pitt.edu/36064/. We include a basic summary of the strategy of the DEEP3 Galaxy Redshift Survey to accompany the recent public release of DEEP3 data.
Dark Energy Survey Year 1 results: validation of weak lensing cluster member contamination estimates from P(z) decompositionVarga, T. N.DeRose, J.Gruen, D.McClintock, T.Seitz, S.Rozo, E.Costanzi, M.Hoyle, B.MacCrann, N.Plazas, A. A.Rykoff, E. S.Simet, M.von der Linden, A.Wechsler, R. H.Annis, J.Avila, S.Bertin, E.Brooks, D.Buckley-Geer, E.Burke, D. L.Carnero Rosell, A.Carrasco Kind, M.Carretero, J.Cunha, C. E.D'Andrea, C. B.da Costa, L. N.De Vicente, J.Desai, S.Diehl, H. T.Dietrich, J. P.Doel, P.Evrard, A. E.Flaugher, B.Fosalba, P.Frieman, J.García-Bellido, J.Gaztanaga, E.Gerdes, D. W.Gruendl, R. A.Gschwend, J.Gutierrez, G.Hartley, W. G.Hollowood, D. L.Honscheid, K.James, David J.Jeltema, T.Kuehn, K.Kuropatkin, N.Lima, M.Maia, M. A. G.March, M.Marshall, J. L.Melchior, P.Menanteau, F.Miller, C. J.Miquel, R.Ogando, R. L. C.Romer, A. K.Sanchez, E.Scarpine, V.Schubnell, M.Serrano, S.Sevilla-Noarbe, I.Smith, M.Sobreira, F.Suchyta, E.Swanson, M. E. C.Tarle, G.Thomas, D.Tucker, D. L.Zhang, Y.DES Collaboration2019DOI: info:10.1093/mnras/stz2185Monthly Notices of the Royal Astronomical Societyv. 489 2511 25242511–25240035-8711
Varga, T. N., DeRose, J., Gruen, D., McClintock, T., Seitz, S., Rozo, E., Costanzi, M., Hoyle, B., MacCrann, N., Plazas, A. A., Rykoff, E. S., Simet, M., von der Linden, A., Wechsler, R. H., Annis, J., Avila, S., Bertin, E., Brooks, D., Buckley-Geer, E., Burke, D. L., Carnero Rosell, A., Carrasco Kind, M., Carretero, J., Cunha, C. E., D'Andrea, C. B. et al. 2019. "Dark Energy Survey Year 1 results: validation of weak lensing cluster member contamination estimates from P(z) decomposition." Monthly Notices of the Royal Astronomical Society 489: 2511– 2524. https://doi.org/10.1093/mnras/stz2185
ID: 154697
Type: article
Authors: Varga, T. N.; DeRose, J.; Gruen, D.; McClintock, T.; Seitz, S.; Rozo, E.; Costanzi, M.; Hoyle, B.; MacCrann, N.; Plazas, A. A.; Rykoff, E. S.; Simet, M.; von der Linden, A.; Wechsler, R. H.; Annis, J.; Avila, S.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; De Vicente, J.; Desai, S.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Evrard, A. E.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gaztanaga, E.; Gerdes, D. W.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Hartley, W. G.; Hollowood, D. L.; Honscheid, K.; James, David J.; Jeltema, T.; Kuehn, K.; Kuropatkin, N.; Lima, M.; Maia, M. A. G.; March, M.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Miller, C. J.; Miquel, R.; Ogando, R. L. C.; Romer, A. K.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Serrano, S.; Sevilla-Noarbe, I.; Smith, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Tucker, D. L.; Zhang, Y.; DES Collaboration
Keywords: SAO
Abstract: Weak lensing source galaxy catalogues used in estimating the masses of galaxy clusters can be heavily contaminated by cluster members, prohibiting accurate mass calibration. In this study, we test the performance of an estimator for the extent of cluster member contamination based on decomposing the photometric redshift P(z) of source galaxies into contaminating and background components. We perform a full scale mock analysis on a simulated sky survey approximately mirroring the observational properties of the Dark Energy Survey Year One observations (DES Y1), and find excellent agreement between the true number profile of contaminating cluster member galaxies in the simulation and the estimated one. We further apply the method to estimate the cluster member contamination for the DES Y1 redMaPPer cluster mass calibration analysis, and compare the results to an alternative approach based on the angular correlation of weak lensing source galaxies. We find indications that the correlation based estimates are biased by the selection of the weak lensing sources in the cluster vicinity, which does not strongly impact the P(z) decomposition method. Collectively, these benchmarks demonstrate the strength of the P(z) decomposition method in alleviating membership contamination and enabling highly accurate cluster weak lensing studies without broad exclusion of source galaxies, thereby improving the total constraining power of cluster mass calibration via weak lensing.
Interstellar Glycolaldehyde, Methyl Formate, and Acetic Acid. I. A Bimodal Abundance Pattern in Star-forming RegionsEl-Abd, Samer J.Brogan, Crystal L.Hunter, Todd R.Willis, Eric R.Garrod, Robin T.McGuire, Brett A.2019DOI: info:10.3847/1538-4357/ab3646The Astrophysical Journalv. 883 129 1290004-637X
El-Abd, Samer J., Brogan, Crystal L., Hunter, Todd R., Willis, Eric R., Garrod, Robin T., and McGuire, Brett A. 2019. "Interstellar Glycolaldehyde, Methyl Formate, and Acetic Acid. I. A Bimodal Abundance Pattern in Star-forming Regions." The Astrophysical Journal 883: 129. https://doi.org/10.3847/1538-4357/ab3646
ID: 154698
Type: article
Authors: El-Abd, Samer J.; Brogan, Crystal L.; Hunter, Todd R.; Willis, Eric R.; Garrod, Robin T.; McGuire, Brett A.
Keywords: SAO
Abstract: The relative column densities of the structural isomers methyl formate, glycolaldehyde, and acetic acid are derived for a dozen positions toward the massive star-forming regions MM1 and MM2 in the NGC 6334I complex, which are separated by ̃4000 au. Relative column densities of these molecules are also gathered from the literature for 13 other star-forming regions. In this combined data set, a clear bimodal distribution is observed in the relative column densities of glycolaldehyde and methyl formate. No such distribution is evident with acetic acid. The two trends are comprised of star-forming regions with a variety of masses, suggesting that there must be some other common parameter that is heavily impacting the formation of glycolaldehyde. This is indicative of some demonstrable differentiation in these cores; studying the abundances of these isomers may provide a clue as to the integral chemical processes ongoing in a variety of protostellar environments.
KFPA Examinations of Young STellar Object Natal Environments (KEYSTONE): Hierarchical Ammonia Structures in Galactic Giant Molecular CloudsKeown, Jareddi Francesco, JamesRosolowsky, ErikSingh, AyushiFigura, CharlesKirk, HelenAnderson, L. D.Chen, Michael Chun-YuanElia, DavideFriesen, RachelGinsburg, AdamMarston, A.Pezzuto, StefanoSchisano, EugenioBontemps, SylvainCaselli, PaolaLiu, Hong-LiLongmore, StevenMotte, FrédériqueMyers, Philip C.Offner, Stella S. R.Sanhueza, PatricioSchneider, NicolaStephens, IanUrquhart, James2019DOI: info:10.3847/1538-4357/ab3e76The Astrophysical Journalv. 884 4 40004-637X
Keown, Jared, di Francesco, James, Rosolowsky, Erik, Singh, Ayushi, Figura, Charles, Kirk, Helen, Anderson, L. D., Chen, Michael Chun-Yuan, Elia, Davide, Friesen, Rachel, Ginsburg, Adam, Marston, A., Pezzuto, Stefano, Schisano, Eugenio, Bontemps, Sylvain, Caselli, Paola, Liu, Hong-Li, Longmore, Steven, Motte, Frédérique, Myers, Philip C., Offner, Stella S. R., Sanhueza, Patricio, Schneider, Nicola, Stephens, Ian, and Urquhart, James. 2019. "KFPA Examinations of Young STellar Object Natal Environments (KEYSTONE): Hierarchical Ammonia Structures in Galactic Giant Molecular Clouds." The Astrophysical Journal 884: 4. https://doi.org/10.3847/1538-4357/ab3e76
ID: 154699
Type: article
Authors: Keown, Jared; di Francesco, James; Rosolowsky, Erik; Singh, Ayushi; Figura, Charles; Kirk, Helen; Anderson, L. D.; Chen, Michael Chun-Yuan; Elia, Davide; Friesen, Rachel; Ginsburg, Adam; Marston, A.; Pezzuto, Stefano; Schisano, Eugenio; Bontemps, Sylvain; Caselli, Paola; Liu, Hong-Li; Longmore, Steven; Motte, Frédérique; Myers, Philip C.; Offner, Stella S. R.; Sanhueza, Patricio; Schneider, Nicola; Stephens, Ian; Urquhart, James
Keywords: SAO
Abstract: We present initial results from the K-band Focal Plane Array Examinations of Young STellar Object Natal Environments survey, a large project on the 100 m Green Bank Telescope mapping ammonia emission across 11 giant molecular clouds at distances of 0.9-3.0 kpc (Cygnus X North, Cygnus X South, M16, M17, Mon R1, Mon R2, NGC 2264, NGC 7538, Rosette, W3, and W48). This data release includes the NH3 (1,1) and (2,2) maps for each cloud, which are modeled to produce maps of kinetic temperature, centroid velocity, velocity dispersion, and ammonia column density. Median cloud kinetic temperatures range from 11.4 ± 2.2 K in the coldest cloud (Mon R1) to 23.0 ± 6.5 K in the warmest cloud (M17). Using dendrograms on the NH3 (1,1) integrated intensity maps, we identify 856 dense gas clumps across the 11 clouds. Depending on the cloud observed, 40%-100% of the clumps are aligned spatially with filaments identified in H2 column density maps derived from spectral energy distribution fitting of dust continuum emission. A virial analysis reveals that 523 of the 835 clumps (̃63%) with mass estimates are bound by gravity alone. We find no significant difference between the virial parameter distributions for clumps aligned with the dust-continuum filaments and those unaligned with filaments. In some clouds, however, hubs or ridges of dense gas with unusually high mass and low virial parameters are located within a single filament or at the intersection of multiple filaments. These hubs and ridges tend to host water maser emission, multiple 70 μm detected protostars, and have masses and radii above an empirical threshold for forming massive stars.
A Census of Early-phase High-mass Star Formation in the Central Molecular ZoneLu, XingMills, Elisabeth A. C.Ginsburg, AdamWalker, Daniel L.Barnes, Ashley T.Butterfield, NatalieHenshaw, Jonathan D.Battersby, CaraKruijssen, J. M. DiederikLongmore, Steven N.Zhang, QizhouBally, JohnKauffmann, JensOtt, JürgenRickert, MatthewWang, Ke2019DOI: info:10.3847/1538-4365/ab4258The Astrophysical Journal Supplement Seriesv. 244 35 350067-0049
Lu, Xing, Mills, Elisabeth A. C., Ginsburg, Adam, Walker, Daniel L., Barnes, Ashley T., Butterfield, Natalie, Henshaw, Jonathan D., Battersby, Cara, Kruijssen, J. M. Diederik, Longmore, Steven N., Zhang, Qizhou, Bally, John, Kauffmann, Jens, Ott, Jürgen, Rickert, Matthew, and Wang, Ke. 2019. "A Census of Early-phase High-mass Star Formation in the Central Molecular Zone." The Astrophysical Journal Supplement Series 244: 35. https://doi.org/10.3847/1538-4365/ab4258
ID: 154700
Type: article
Authors: Lu, Xing; Mills, Elisabeth A. C.; Ginsburg, Adam; Walker, Daniel L.; Barnes, Ashley T.; Butterfield, Natalie; Henshaw, Jonathan D.; Battersby, Cara; Kruijssen, J. M. Diederik; Longmore, Steven N.; Zhang, Qizhou; Bally, John; Kauffmann, Jens; Ott, Jürgen; Rickert, Matthew; Wang, Ke
Keywords: SAO
Abstract: We present new observations of the C-band continuum emission and masers to assess high-mass (>8 {M}) star formation at early evolutionary phases in the inner 200 pc of the Central Molecular Zone (CMZ) of the Galaxy. The continuum observation is complete to free-free emission from stars above 10-11 {M} in 91% of the covered area. We identify 104 compact sources in the continuum emission, among which five are confirmed ultracompact H II regions, 12 are candidates of ultracompact H II regions, and the remaining 87 sources are mostly massive stars in clusters, field stars, evolved stars, pulsars, extragalactic sources, or of unknown nature that is to be investigated. We detect class II CH3OH masers at 23 positions, among which six are new detections. We confirm six known H2CO masers in two high-mass star-forming regions and detect two new H2CO masers toward the Sgr C cloud, making it the ninth region in the Galaxy that contains masers of this type. In spite of these detections, we find that current high-mass star formation in the inner CMZ is only taking place in seven isolated clouds. The results suggest that star formation at early evolutionary phases in the CMZ is about 10 times less efficient than expected from the dense gas star formation relation, which is in line with previous studies that focus on more evolved phases of star formation. This means that if there will be any impending, next burst of star formation in the CMZ, it has not yet begun.
KMT-2018-BLG-1990Lb: A Nearby Jovian Planet From A Low-cadence Microlensing FieldRyu, Yoon-HyunHwang, Kyu-HaGould, AndrewAlbrow, Michael D.Chung, Sun-JuHan, CheonghoJung, Youn KilShin, In-GuShvartzvald, YossiYee, Jennifer C.Zang, WeichengCha, Sang-MokKim, Dong-JinKim, Hyoun-WooKim, Seung-LeeLee, Chung-UkLee, Dong-JooLee, YongseokPark, Byeong-GonPogge, Richard W.2019DOI: info:10.3847/1538-3881/ab3a34The Astronomical Journalv. 158 151 1510004-6256
Ryu, Yoon-Hyun, Hwang, Kyu-Ha, Gould, Andrew, Albrow, Michael D., Chung, Sun-Ju, Han, Cheongho, Jung, Youn Kil, Shin, In-Gu, Shvartzvald, Yossi, Yee, Jennifer C., Zang, Weicheng, Cha, Sang-Mok, Kim, Dong-Jin, Kim, Hyoun-Woo, Kim, Seung-Lee, Lee, Chung-Uk, Lee, Dong-Joo, Lee, Yongseok, Park, Byeong-Gon, and Pogge, Richard W. 2019. "KMT-2018-BLG-1990Lb: A Nearby Jovian Planet From A Low-cadence Microlensing Field." The Astronomical Journal 158: 151. https://doi.org/10.3847/1538-3881/ab3a34
ID: 154701
Type: article
Authors: Ryu, Yoon-Hyun; Hwang, Kyu-Ha; Gould, Andrew; Albrow, Michael D.; Chung, Sun-Ju; Han, Cheongho; Jung, Youn Kil; Shin, In-Gu; Shvartzvald, Yossi; Yee, Jennifer C.; Zang, Weicheng; Cha, Sang-Mok; Kim, Dong-Jin; Kim, Hyoun-Woo; Kim, Seung-Lee; Lee, Chung-Uk; Lee, Dong-Joo; Lee, Yongseok; Park, Byeong-Gon; Pogge, Richard W.
Keywords: SAO
Abstract: We report the discovery of KMT-2018-BLG-1990Lb, a Jovian planet ({m}p={0.57}-0.25+0.79 {M}J) orbiting a late M dwarf (M={0.14}-0.06+0.20 {M}) at a distance of ({D}L={1.23}-0.43+1.06 {kpc}), and projected at 2.6 ± 0.6 times the snow line distance, i.e., {a}snow}\equiv 2.7 {au}(M/{M}). This is the second Jovian planet discovered by the Korea Microlensing Telescope Network (KMTNet) in its low-cadence (0.4 hr-1) fields, demonstrating that this population can be probed based on relatively low-cadence survey-only microlensing data. However, while many Jovian- planet microlensing events will not have caustic crossings (e.g., the previous case, KMT-2016-BLG-1397) and some that do will be well characterized by low-cadence survey observations (e.g., the current case), in general higher-cadence follow-up observations of the caustic crossings are preferable. Such follow-up observations require microlensing alerts, which KMTNet now provides.
Radio Spectroscopic Imaging of a Solar Flare Termination Shock: Split-band Feature as Evidence for Shock CompressionChen, BinShen, ChengcaiReeves, Katharine K.Guo, FanYu, Sijie2019DOI: info:10.3847/1538-4357/ab3c58The Astrophysical Journalv. 884 63 630004-637X
Chen, Bin, Shen, Chengcai, Reeves, Katharine K., Guo, Fan, and Yu, Sijie. 2019. "Radio Spectroscopic Imaging of a Solar Flare Termination Shock: Split-band Feature as Evidence for Shock Compression." The Astrophysical Journal 884: 63. https://doi.org/10.3847/1538-4357/ab3c58
ID: 154702
Type: article
Authors: Chen, Bin; Shen, Chengcai; Reeves, Katharine K.; Guo, Fan; Yu, Sijie
Keywords: SAO
Abstract: Solar flare termination shocks have been suggested as one of the promising drivers for particle acceleration in solar flares, yet observational evidence remains rare. By utilizing radio dynamic spectroscopic imaging of decimetric stochastic spike bursts in an eruptive flare, Chen et al. found that the bursts form a dynamic surface-like feature located at the ending points of fast plasma downflows above the looptop, interpreted as a flare termination shock. One piece of observational evidence that strongly supports the termination shock interpretation is the occasional split of the emission band into two finer lanes in frequency, similar to the split-band feature seen in fast-coronal-shock-driven type II radio bursts. Here, we perform spatially, spectrally, and temporally resolved analysis of the split-band feature of the flare termination shock event. We find that the ensemble of the radio centroids from the two split-band lanes each outlines a nearly co-spatial surface. The high-frequency lane is located slightly below its low-frequency counterpart by ̃0.8 Mm, which strongly supports the shock-upstream-downstream interpretation. Under this scenario, the density compression ratio across the shock front can be inferred from the frequency split, which implies a shock with a Mach number of up to 2.0. Further, the spatiotemporal evolution of the density compression along the shock front agrees favorably with results from magnetohydrodynamics simulations. We conclude that the detailed variations of the shock compression ratio may be due to the impact of dynamic plasma structures in the reconnection outflows, which results in distortion of the shock front.
A DECam Search for Explosive Optical Transients Associated with IceCube Neutrino AlertsMorgan, R.Bechtol, K.Kessler, R.Sako, M.Herner, K.Doctor, Z.Scolnic, D.Sevilla-Noarbe, I.Franckowiak, A.Neilson, K. N.Kowalski, M.Palmese, A.Swann, E.Thomas, B. P.Vivas, A. K.Drlica-Wagner, A.Garcia, A.Brout, D.Paz-Chinchón, F.Neilsen, E.Diehl, H. T.Soares-Santos, M.Abbott, T. M. C.Avila, S.Bertin, E.Brooks, D.Buckley-Geer, E.Carnero Rosell, A.Carrasco Kind, M.Carretero, J.Cawthon, R.Costanzi, M.De Vicente, J.Desai, S.Doel, P.Flaugher, B.Fosalba, P.Frieman, J.García-Bellido, J.Gaztanaga, E.Gerdes, D. W.Gruen, D.Gruendl, R. A.Gschwend, J.Gutierrez, G.Hollowood, D. L.Honscheid, K.James, David J.Kuropatkin, N.Lima, M.Maia, M. A. G.Marshall, J. L.Menanteau, F.Miller, C. J.Miquel, R.Plazas, A. A.Sanchez, E.Scarpine, V.Schubnell, M.Serrano, S.Smith, M.Sobreira, F.Suchyta, E.Swanson, M. E. C.Tarle, G.Vikram, V.Walker, A. R.Weller, J.2019DOI: info:10.3847/1538-4357/ab3a45The Astrophysical Journalv. 883 125 1250004-637X
Morgan, R., Bechtol, K., Kessler, R., Sako, M., Herner, K., Doctor, Z., Scolnic, D., Sevilla-Noarbe, I., Franckowiak, A., Neilson, K. N., Kowalski, M., Palmese, A., Swann, E., Thomas, B. P., Vivas, A. K., Drlica-Wagner, A., Garcia, A., Brout, D., Paz-Chinchón, F., Neilsen, E., Diehl, H. T., Soares-Santos, M., Abbott, T. M. C., Avila, S., Bertin, E. et al. 2019. "A DECam Search for Explosive Optical Transients Associated with IceCube Neutrino Alerts." The Astrophysical Journal 883: 125. https://doi.org/10.3847/1538-4357/ab3a45
ID: 154703
Type: article
Authors: Morgan, R.; Bechtol, K.; Kessler, R.; Sako, M.; Herner, K.; Doctor, Z.; Scolnic, D.; Sevilla-Noarbe, I.; Franckowiak, A.; Neilson, K. N.; Kowalski, M.; Palmese, A.; Swann, E.; Thomas, B. P.; Vivas, A. K.; Drlica-Wagner, A.; Garcia, A.; Brout, D.; Paz-Chinchón, F.; Neilsen, E.; Diehl, H. T.; Soares-Santos, M.; Abbott, T. M. C.; Avila, S.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Cawthon, R.; Costanzi, M.; De Vicente, J.; Desai, S.; Doel, P.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gaztanaga, E.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Hollowood, D. L.; Honscheid, K.; James, David J.; Kuropatkin, N.; Lima, M.; Maia, M. A. G.; Marshall, J. L.; Menanteau, F.; Miller, C. J.; Miquel, R.; Plazas, A. A.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Serrano, S.; Smith, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Vikram, V.; Walker, A. R.; Weller, J.
Keywords: SAO
Abstract: In this work, we investigate the likelihood of association between real-time, neutrino alerts with teraelectronvolt to petaelectronvolt energy from IceCube and optical counterparts in the form of core-collapse supernovae (CC SNe). The optical follow-up of IceCube alerts requires two main instrumental capabilities: (1) deep imaging, since 73% of neutrinos would come from CC SNe at redshifts z > 0.3, and (2) a large field of view (FoV), since typical IceCube muon neutrino pointing accuracy is on the order of ∼1 deg. With Blanco/DECam (gri to 24th magnitude and 2.2 deg diameter FoV), we performed a triggered optical follow-up observation of two IceCube alerts, IC170922A and IC171106A, on six nights during the three weeks following each alert. For the IC170922A (IC171106A) follow-up observations, we expect that 12.1% (9.5%) of coincident CC SNe at z ≲ 0.3 are detectable, and that, on average, 0.23 (0.07) unassociated SNe in the neutrino 90% containment regions also pass our selection criteria. We find two candidate CC SNe that are temporally coincident with the neutrino alerts in the FoV, but none in the 90% containment regions, a result that is statistically consistent with expected rates of background CC SNe for these observations. If CC SNe are the dominant source of teraelectronvolt to petaelectronvolt neutrinos, we would expect an excess of coincident CC SNe to be detectable at the 3σ confidence level using DECam observations similar to those of this work for ∼60 (∼200) neutrino alerts with (without) redshift information for all candidates.
Searches for Interstellar HCCSH and H2CCSMcGuire, Brett A.Shingledecker, Christopher N.Willis, Eric R.Lee, Kin Long KelvinMartin-Drumel, Marie-AlineBlake, Geoffrey A.Brogan, Crystal L.Burkhardt, Andrew M.Caselli, PaolaChuang, Ko-JuEl-Abd, SamerHunter, Todd R.Ioppolo, SergioLinnartz, HaroldRemijan, Anthony J.Xue, CiMcCarthy, Michael C.2019DOI: info:10.3847/1538-4357/ab3b01The Astrophysical Journalv. 883 201 2010004-637X
McGuire, Brett A., Shingledecker, Christopher N., Willis, Eric R., Lee, Kin Long Kelvin, Martin-Drumel, Marie-Aline, Blake, Geoffrey A., Brogan, Crystal L., Burkhardt, Andrew M., Caselli, Paola, Chuang, Ko-Ju, El-Abd, Samer, Hunter, Todd R., Ioppolo, Sergio, Linnartz, Harold, Remijan, Anthony J., Xue, Ci, and McCarthy, Michael C. 2019. "Searches for Interstellar HCCSH and H2CCS." The Astrophysical Journal 883: 201. https://doi.org/10.3847/1538-4357/ab3b01
ID: 154704
Type: article
Authors: McGuire, Brett A.; Shingledecker, Christopher N.; Willis, Eric R.; Lee, Kin Long Kelvin; Martin-Drumel, Marie-Aline; Blake, Geoffrey A.; Brogan, Crystal L.; Burkhardt, Andrew M.; Caselli, Paola; Chuang, Ko-Ju; El-Abd, Samer; Hunter, Todd R.; Ioppolo, Sergio; Linnartz, Harold; Remijan, Anthony J.; Xue, Ci; McCarthy, Michael C.
Keywords: SAO
Abstract: A longstanding problem in astrochemistry is the inability of many current models to account for missing sulfur content. Many relatively simple species that may be good candidates to sequester sulfur have not been measured experimentally at the high spectral resolution necessary to enable radioastronomical identification. On the basis of new laboratory data, we report searches for the rotational lines in the microwave, millimeter, and submillimeter regions of the sulfur- containing hydrocarbon HCCSH. This simple species would appear to be a promising candidate for detection in space owing to the large dipole moment along its b-inertial axis, and because the bimolecular reaction between two highly abundant astronomical fragments (CCH and SH radicals) may be rapid. An inspection of multiple line surveys from the centimeter to the far-infrared toward a range of sources from dark clouds to high- mass star-forming regions, however, resulted in nondetections. An analogous search for the lowest-energy isomer, {{{H}}}2{CCS}, is presented for comparison, and also resulted in nondetections. Typical upper limits on the abundance of both species relative to hydrogen are 10-9-10-10. We thus conclude that neither isomer is a major reservoir of interstellar sulfur in the range of environments studied. Both species may still be viable candidates for detection in other environments or at higher frequencies, providing laboratory frequencies are available.
The ALMA Discovery of the Rotating Disk and Fast Outflow of Cold Molecular Gas in NGC 1275Nagai, H.Onishi, K.Kawakatu, N.Fujita, Y.Kino, M.Fukazawa, Y.Lim, J.Forman, WilliamVrtilek, JanNakanishi, K.Noda, H.Asada, K.Wajima, K.Ohyama, Y.David, LaurenceDaikuhara, K.2019DOI: info:10.3847/1538-4357/ab3e6eThe Astrophysical Journalv. 883 193 1930004-637X
Nagai, H., Onishi, K., Kawakatu, N., Fujita, Y., Kino, M., Fukazawa, Y., Lim, J., Forman, William, Vrtilek, Jan, Nakanishi, K., Noda, H., Asada, K., Wajima, K., Ohyama, Y., David, Laurence, and Daikuhara, K. 2019. "The ALMA Discovery of the Rotating Disk and Fast Outflow of Cold Molecular Gas in NGC 1275." The Astrophysical Journal 883: 193. https://doi.org/10.3847/1538-4357/ab3e6e
ID: 154705
Type: article
Authors: Nagai, H.; Onishi, K.; Kawakatu, N.; Fujita, Y.; Kino, M.; Fukazawa, Y.; Lim, J.; Forman, William; Vrtilek, Jan; Nakanishi, K.; Noda, H.; Asada, K.; Wajima, K.; Ohyama, Y.; David, Laurence; Daikuhara, K.
Keywords: SAO
Abstract: We present observations using the Atacama Large Millimeter/submillimeter Array of the CO(2-1), HCN(3-2), and HCO+(3-2) lines in the nearby radio galaxy/brightest cluster galaxy (BCG) NGC 1275 with a spatial resolution of ̃20 pc. In previous observations, the CO(2-1) emission was detected as radial filaments lying in the east-west direction on a kiloparsec scale. We resolved the inner filament and found that it cannot be represented by a simple infalling stream on a sub-kiloparsec scale. The observed complex nature of the filament resembles the cold gas structure predicted by numerical simulations of cold chaotic accretion. Within the central 100 pc, we detected a rotational disk of molecular gas whose mass is ̃108 M . This is the first evidence of the presence of a massive cold gas disk on this spatial scale for BCGs. A crude estimate suggests that the accretion rate of the cold gas can be higher than that of hot gas. The disk rotation axis is approximately consistent with the radio- jet axis. This probably suggests that the cold gas disk is physically connected to the innermost accretion disk, which is responsible for jet launching. We also detected absorption features in the HCN(3-2) and HCO+(3-2) spectra against the radio continuum emission mostly radiated by a jet of size ̃1.2 pc. The absorption features are blueshifted from the systemic velocity by ̃300-600 km s-1, suggesting the presence of outflowing gas from the active galactic nucleus (AGN). We discuss the relation of the AGN feeding with cold accretion, the origin of blueshifted absorption, and an estimate of the black hole mass using molecular gas dynamics.
Planetesimals around stars with TESS (PAST) - I. Transient dimming of a binary solar analogue at the end of the planet accretion eraGaidos, E.Jacobs, T.LaCourse, D.Vanderburg, A.Rappaport, S.Berger, T.Pearce, L.Mann, A. W.Weiss, L.Fulton, B.Behmard, A.Howard, A. W.Ansdell, M.Ricker, G. R.Vanderspek, R. K.Latham, David W.Seager, S.Winn, J. N.Jenkins, J. M.2019DOI: info:10.1093/mnras/stz1942Monthly Notices of the Royal Astronomical Societyv. 488 4465 44764465–44760035-8711
Gaidos, E., Jacobs, T., LaCourse, D., Vanderburg, A., Rappaport, S., Berger, T., Pearce, L., Mann, A. W., Weiss, L., Fulton, B., Behmard, A., Howard, A. W., Ansdell, M., Ricker, G. R., Vanderspek, R. K., Latham, David W., Seager, S., Winn, J. N., and Jenkins, J. M. 2019. "Planetesimals around stars with TESS (PAST) - I. Transient dimming of a binary solar analogue at the end of the planet accretion era." Monthly Notices of the Royal Astronomical Society 488: 4465– 4476. https://doi.org/10.1093/mnras/stz1942
ID: 154706
Type: article
Authors: Gaidos, E.; Jacobs, T.; LaCourse, D.; Vanderburg, A.; Rappaport, S.; Berger, T.; Pearce, L.; Mann, A. W.; Weiss, L.; Fulton, B.; Behmard, A.; Howard, A. W.; Ansdell, M.; Ricker, G. R.; Vanderspek, R. K.; Latham, David W.; Seager, S.; Winn, J. N.; Jenkins, J. M.
Keywords: SAO
Abstract: We report detection of quasi-periodic (1.5-d) dimming of HD 240779, the solar-mass primary in a 5 arcsec visual binary (also TIC 284730577), by the Transiting Exoplanet Survey Satellite. This dimming, as has been shown for other `dipper' stars, is likely due to occultation by circumstellar dust. The barycentric space motion, lithium abundance, rotation, and chromospheric emission of the stars in this system point to an age of ≈125 Myr, and possible membership in the AB Doradus moving group. As such it occupies an important but poorly explored intermediate regime of stars with transient dimming between young stellar objects in star-forming regions and main-sequence stars, and between UX Orionis- type Ae/Be stars and M-type `dippers'. HD 240779, but not its companion BD+10 714B, has Wide-field Infrared Survey Explorer (WISE)-detected excess infrared emission at 12 and 22 μm indicative of circumstellar dust. We propose that infrared emission is produced by collisions of planetesimals during clearing of a residual disc at the end of rocky planet formation, and that quasi-periodic dimming is produced by the rapid disintegration of a ≳100 km planetesimal near the silicate evaporation radius. Further studies of this and similar systems will illuminate a poorly understood final phase of rocky planet formation like that which produced the inner Solar system.
Constraining cold accretion on to supermassive black holes: molecular gas in the cores of eight brightest cluster galaxies revealed by joint CO and CN absorptionRose, TomEdge, A. C.Combes, F.Gaspari, M.Hamer, S.Nesvadba, N.Peck, A. B.Sarazin, C.Tremblay, Grant R.Baum, S. A.Bremer, M. N.McNamara, B. R.O'Dea, C.Oonk, J. B. R.Russell, H.Salomé, P.Donahue, M.Fabian, A. C.Ferland, G.Mittal, R.Vantyghem, A.2019DOI: info:10.1093/mnras/stz2138Monthly Notices of the Royal Astronomical Societyv. 489 349 365349–3650035-8711
Rose, Tom, Edge, A. C., Combes, F., Gaspari, M., Hamer, S., Nesvadba, N., Peck, A. B., Sarazin, C., Tremblay, Grant R., Baum, S. A., Bremer, M. N., McNamara, B. R., O'Dea, C., Oonk, J. B. R., Russell, H., Salomé, P., Donahue, M., Fabian, A. C., Ferland, G., Mittal, R., and Vantyghem, A. 2019. "Constraining cold accretion on to supermassive black holes: molecular gas in the cores of eight brightest cluster galaxies revealed by joint CO and CN absorption." Monthly Notices of the Royal Astronomical Society 489: 349– 365. https://doi.org/10.1093/mnras/stz2138
ID: 154707
Type: article
Authors: Rose, Tom; Edge, A. C.; Combes, F.; Gaspari, M.; Hamer, S.; Nesvadba, N.; Peck, A. B.; Sarazin, C.; Tremblay, Grant R.; Baum, S. A.; Bremer, M. N.; McNamara, B. R.; O'Dea, C.; Oonk, J. B. R.; Russell, H.; Salomé, P.; Donahue, M.; Fabian, A. C.; Ferland, G.; Mittal, R.; Vantyghem, A.
Keywords: SAO
Abstract: To advance our understanding of the fuelling and feedback processes which power the Universe's most massive black holes, we require a significant increase in our knowledge of the molecular gas which exists in their immediate surroundings. However, the behaviour of this gas is poorly understood due to the difficulties associated with observing it directly. We report on a survey of 18 brightest cluster galaxies lying in cool cores, from which we detect molecular gas in the core regions of eight via carbon monoxide (CO), cyanide (CN) and silicon monoxide (SiO) absorption lines. These absorption lines are produced by cold molecular gas clouds which lie along the line of sight to the bright continuum sources at the galaxy centres. As such, they can be used to determine many properties of the molecular gas which may go on to fuel supermassive black hole accretion and AGN feedback mechanisms. The absorption regions detected have velocities ranging from -45 to 283 km s-1 relative to the systemic velocity of the galaxy, and have a bias for motion towards the host supermassive black hole. We find that the CN N = 0 - 1 absorption lines are typically 10 times stronger than those of CO J = 0 - 1. This is due to the higher electric dipole moment of the CN molecule, which enhances its absorption strength. In terms of molecular number density CO remains the more prevalent molecule with a ratio of CO/CN ̃10, similar to that of nearby galaxies. Comparison of CO, CN, and H I observations for these systems shows many different combinations of these absorption lines being detected.
Phenotypic redshifts with self-organizing maps: A novel method to characterize redshift distributions of source galaxies for weak lensingBuchs, R.Davis, C.Gruen, D.DeRose, J.Alarcon, A.Bernstein, G. M.Sánchez, C.Myles, J.Roodman, A.Allen, S.Amon, A.Choi, A.Masters, D. C.Miquel, R.Troxel, M. A.Wechsler, R. H.Abbott, T. M. C.Annis, J.Avila, S.Bechtol, K.Bridle, S. L.Brooks, D.Buckley-Geer, E.Burke, D. L.Carnero Rosell, A.Carrasco Kind, M.Carretero, J.Castander, F. J.Cawthon, R.D'Andrea, C. B.da Costa, L. N.De Vicente, J.Desai, S.Diehl, H. T.Doel, P.Drlica-Wagner, A.Eifler, T. F.Evrard, A. E.Flaugher, B.Fosalba, P.Frieman, J.García-Bellido, J.Gaztanaga, E.Gruendl, R. A.Gschwend, J.Gutierrez, G.Hartley, W. G.Hollowood, D. L.Honscheid, K.James, David J.Kuehn, K.Kuropatkin, N.Lima, M.Lin, H.Maia, M. A. G.March, M.Marshall, J. L.Melchior, P.Menanteau, F.Ogando, R. L. C.Plazas, A. A.Rykoff, E. S.Sanchez, E.Scarpine, V.Serrano, S.Sevilla-Noarbe, I.Smith, M.Soares-Santos, M.Sobreira, F.Suchyta, E.Swanson, M. E. C.Tarle, G.Thomas, D.Vikram, V.DES Collaboration2019DOI: info:10.1093/mnras/stz2162Monthly Notices of the Royal Astronomical Societyv. 489 820 841820–8410035-8711
Buchs, R., Davis, C., Gruen, D., DeRose, J., Alarcon, A., Bernstein, G. M., Sánchez, C., Myles, J., Roodman, A., Allen, S., Amon, A., Choi, A., Masters, D. C., Miquel, R., Troxel, M. A., Wechsler, R. H., Abbott, T. M. C., Annis, J., Avila, S., Bechtol, K., Bridle, S. L., Brooks, D., Buckley-Geer, E., Burke, D. L., Carnero Rosell, A. et al. 2019. "Phenotypic redshifts with self-organizing maps: A novel method to characterize redshift distributions of source galaxies for weak lensing." Monthly Notices of the Royal Astronomical Society 489: 820– 841. https://doi.org/10.1093/mnras/stz2162
ID: 154708
Type: article
Authors: Buchs, R.; Davis, C.; Gruen, D.; DeRose, J.; Alarcon, A.; Bernstein, G. M.; Sánchez, C.; Myles, J.; Roodman, A.; Allen, S.; Amon, A.; Choi, A.; Masters, D. C.; Miquel, R.; Troxel, M. A.; Wechsler, R. H.; Abbott, T. M. C.; Annis, J.; Avila, S.; Bechtol, K.; Bridle, S. L.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Castander, F. J.; Cawthon, R.; D'Andrea, C. B.; da Costa, L. N.; De Vicente, J.; Desai, S.; Diehl, H. T.; Doel, P.; Drlica-Wagner, A.; Eifler, T. F.; Evrard, A. E.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gaztanaga, E.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Hartley, W. G.; Hollowood, D. L.; Honscheid, K.; James, David J.; Kuehn, K.; Kuropatkin, N.; Lima, M.; Lin, H.; Maia, M. A. G.; March, M.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Ogando, R. L. C.; Plazas, A. A.; Rykoff, E. S.; Sanchez, E.; Scarpine, V.; Serrano, S.; Sevilla-Noarbe, I.; Smith, M.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Vikram, V.; DES Collaboration
Keywords: SAO
Abstract: Wide-field imaging surveys such as the Dark Energy Survey (DES) rely on coarse measurements of spectral energy distributions in a few filters to estimate the redshift distribution of source galaxies. In this regime, sample variance, shot noise, and selection effects limit the attainable accuracy of redshift calibration and thus of cosmological constraints. We present a new method to combine wide-field, few-filter measurements with catalogues from deep fields with additional filters and sufficiently low photometric noise to break degeneracies in photometric redshifts. The multiband deep field is used as an intermediary between wide-field observations and accurate redshifts, greatly reducing sample variance, shot noise, and selection effects. Our implementation of the method uses self-organizing maps to group galaxies into phenotypes based on their observed fluxes, and is tested using a mock DES catalogue created from N-body simulations. It yields a typical uncertainty on the mean redshift in each of five tomographic bins for an idealized simulation of the DES Year 3 weak-lensing tomographic analysis of σ∆z = 0.007, which is a 60 per cent improvement compared to the Year 1 analysis. Although the implementation of the method is tailored to DES, its formalism can be applied to other large photometric surveys with a similar observing strategy.
Neutron Stars and Black Holes in the Small Magellanic Cloud: The SMC NuSTAR Legacy SurveyLazzarini, M.Williams, B. F.Hornschemeier, A. E.Antoniou, ValliaVasilopoulos, G.Haberl, F.Vulic, N.Yukita, M.Zezas, AndreasBodaghee, A.Lehmer, B. D.Maccarone, T. J.Ptak, A.Wik, D.Fornasini, Francesca M.Hong, JaesubKennea, J. A.Tomsick, J. A.Venters, T.Udalski, A.Cassity, A.2019DOI: info:10.3847/1538-4357/ab3f32The Astrophysical Journalv. 884 2 20004-637X
Lazzarini, M., Williams, B. F., Hornschemeier, A. E., Antoniou, Vallia, Vasilopoulos, G., Haberl, F., Vulic, N., Yukita, M., Zezas, Andreas, Bodaghee, A., Lehmer, B. D., Maccarone, T. J., Ptak, A., Wik, D., Fornasini, Francesca M., Hong, Jaesub, Kennea, J. A., Tomsick, J. A., Venters, T., Udalski, A., and Cassity, A. 2019. "Neutron Stars and Black Holes in the Small Magellanic Cloud: The SMC NuSTAR Legacy Survey." The Astrophysical Journal 884: 2. https://doi.org/10.3847/1538-4357/ab3f32
ID: 154709
Type: article
Authors: Lazzarini, M.; Williams, B. F.; Hornschemeier, A. E.; Antoniou, Vallia; Vasilopoulos, G.; Haberl, F.; Vulic, N.; Yukita, M.; Zezas, Andreas; Bodaghee, A.; Lehmer, B. D.; Maccarone, T. J.; Ptak, A.; Wik, D.; Fornasini, Francesca M.; Hong, Jaesub; Kennea, J. A.; Tomsick, J. A.; Venters, T.; Udalski, A.; Cassity, A.
Keywords: SAO
Abstract: We present a source catalog from the first deep hard X-ray (E > 10 keV) survey of the Small Magellanic Cloud (SMC), the Nuclear Spectroscopic Telescope Array (NuSTAR) Legacy Survey of the SMC. We observed three fields, for a total exposure time of 1 Ms, along the bar of this nearby star-forming galaxy. Fields were chosen for their young stellar and accreting binary populations. We detected 10 sources above a 3σ significance level (4-25 keV) and obtained upper limits on an additional 40 sources. We reached a 3σ limiting luminosity in the 4-25 keV band of ̃1035 erg s-1, allowing us to probe fainter X-ray binary (XRB) populations than has been possible with other extragalactic NuSTAR surveys. We used hard X-ray colors and luminosities to constrain the compact-object type, exploiting the spectral differences between accreting black holes and neutron stars at E > 10 keV. Several of our sources demonstrate variability consistent with previously observed behavior. We confirmed pulsations for seven pulsars in our 3σ sample. We present the first detection of pulsations from a Be-XRB, SXP 305 (CXO J005215.4-73191), with an X-ray pulse period of 305.69 ± 0.16 s and a likely orbital period of ̃1160-1180 days. Bright sources (≳5 × 1036 erg s-1) in our sample have compact-object classifications consistent with their previously reported types in the literature. Lower-luminosity sources (≲5 × 1036 erg s-1) have X-ray colors and luminosities consistent with multiple classifications. We raise questions about possible spectral differences at low luminosity between SMC pulsars and the Galactic pulsars used to create the diagnostic diagrams.
Methods for cluster cosmology and application to the SDSS in preparation for DES Year 1 releaseCostanzi, M.Rozo, E.Simet, M.Zhang, Y.Evrard, A. E.Mantz, A.Rykoff, E. S.Jeltema, T.Gruen, D.Allen, S.McClintock, T.Romer, A. K.von der Linden, A.Farahi, A.DeRose, J.Varga, T. N.Weller, J.Giles, P.Hollowood, D. L.Bhargava, S.Bermeo-Hernandez, A.Chen, X.Abbott, T. M. C.Abdalla, F. B.Avila, S.Bechtol, K.Brooks, D.Buckley-Geer, E.Burke, D. L.Rosell, A. CarneroKind, M. CarrascoCarretero, J.Crocce, M.Cunha, C. E.da Costa, L. N.Davis, C.De Vicente, J.Diehl, H. T.Dietrich, J. P.Doel, P.Eifler, T. F.Estrada, J.Flaugher, B.Fosalba, P.Frieman, J.García-Bellido, J.Gaztanaga, E.Gerdes, D. W.Giannantonio, T.Gruendl, R. A.Gschwend, J.Gutierrez, G.Hartley, W. G.Honscheid, K.Hoyle, B.James, David J.Krause, E.Kuehn, K.Kuropatkin, N.Lima, M.Lin, H.Maia, M. A. G.March, M.Marshall, J. L.Martini, P.Menanteau, F.Miller, C. J.Miquel, R.Mohr, J. J.Ogando, R. L. C.Plazas, A. A.Roodman, A.Sanchez, E.Scarpine, V.Schindler, R.Schubnell, M.Serrano, S.Sevilla-Noarbe, I.Sheldon, E.Smith, M.Soares-Santos, M.Sobreira, F.Suchyta, E.Swanson, M. E. C.Tarle, G.Thomas, D.Wechsler, R. H.2019DOI: info:10.1093/mnras/stz1949Monthly Notices of the Royal Astronomical Societyv. 488 4779 48004779–48000035-8711
Costanzi, M., Rozo, E., Simet, M., Zhang, Y., Evrard, A. E., Mantz, A., Rykoff, E. S., Jeltema, T., Gruen, D., Allen, S., McClintock, T., Romer, A. K., von der Linden, A., Farahi, A., DeRose, J., Varga, T. N., Weller, J., Giles, P., Hollowood, D. L., Bhargava, S., Bermeo-Hernandez, A., Chen, X., Abbott, T. M. C., Abdalla, F. B., Avila, S. et al. 2019. "Methods for cluster cosmology and application to the SDSS in preparation for DES Year 1 release." Monthly Notices of the Royal Astronomical Society 488: 4779– 4800. https://doi.org/10.1093/mnras/stz1949
ID: 154710
Type: article
Authors: Costanzi, M.; Rozo, E.; Simet, M.; Zhang, Y.; Evrard, A. E.; Mantz, A.; Rykoff, E. S.; Jeltema, T.; Gruen, D.; Allen, S.; McClintock, T.; Romer, A. K.; von der Linden, A.; Farahi, A.; DeRose, J.; Varga, T. N.; Weller, J.; Giles, P.; Hollowood, D. L.; Bhargava, S.; Bermeo-Hernandez, A.; Chen, X.; Abbott, T. M. C.; Abdalla, F. B.; Avila, S.; Bechtol, K.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Rosell, A. Carnero; Kind, M. Carrasco; Carretero, J.; Crocce, M.; Cunha, C. E.; da Costa, L. N.; Davis, C.; De Vicente, J.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Eifler, T. F.; Estrada, J.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gaztanaga, E.; Gerdes, D. W.; Giannantonio, T.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Hartley, W. G.; Honscheid, K.; Hoyle, B.; James, David J.; Krause, E.; Kuehn, K.; Kuropatkin, N.; Lima, M.; Lin, H.; Maia, M. A. G.; March, M.; Marshall, J. L.; Martini, P.; Menanteau, F.; Miller, C. J.; Miquel, R.; Mohr, J. J.; Ogando, R. L. C.; Plazas, A. A.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Serrano, S.; Sevilla-Noarbe, I.; Sheldon, E.; Smith, M.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Wechsler, R. H.
Keywords: SAO
Abstract: We implement the first blind analysis of cluster abundance data to derive cosmological constraints from the abundance and weak lensing signal of redMaPPer clusters in the Sloan Digital Sky Survey (SDSS). We simultaneously fit for cosmological parameters and the richness-mass relation of the clusters. For a flat Λ cold dark matter cosmological model with massive neutrinos, we find S_8 ≡ σ 8(Ω _ m/0.3)^{0.5}=0.79^{+0.05}_{-0.04}. This value is both consistent and competitive with that derived from cluster catalogues selected in different wavelengths. Our result is also consistent with the combined probes analyses by the Dark Energy Survey (DES), the Kilo-Degree Survey (KiDS), and with the cosmic microwave background (CMB) anisotropies as measured by Planck. We demonstrate that the cosmological posteriors are robust against variation of the richness-mass relation model and to systematics associated with the calibration of the selection function. In combination with baryon acoustic oscillation data and big bang nucleosynthesis data (Cooke et al.), we constrain the Hubble rate to be h = 0.66 ± 0.02, independent of the CMB. Future work aimed at improving our understanding of the scatter of the richness-mass relation has the potential to significantly improve the precision of our cosmological posteriors. The methods described in this work were developed for use in the forthcoming analysis of cluster abundances in the DES. Our SDSS analysis constitutes the first part of a staged-unblinding analysis of the full DES data set.
Large-amplitude Quasiperiodic Pulsations as Evidence of Impulsive Heating in Hot Transient Loop Systems Detected in the EUV with SDO/AIAReale, FabioTesta, PaolaPetralia, AntoninoKolotkov, Dmitrii Y.2019DOI: info:10.3847/1538-4357/ab4270The Astrophysical Journalv. 884 131 1310004-637X
Reale, Fabio, Testa, Paola, Petralia, Antonino, and Kolotkov, Dmitrii Y. 2019. "Large-amplitude Quasiperiodic Pulsations as Evidence of Impulsive Heating in Hot Transient Loop Systems Detected in the EUV with SDO/AIA." The Astrophysical Journal 884: 131. https://doi.org/10.3847/1538-4357/ab4270
ID: 154711
Type: article
Authors: Reale, Fabio; Testa, Paola; Petralia, Antonino; Kolotkov, Dmitrii Y.
Keywords: SAO
Abstract: Short heat pulses can trigger plasma pressure fronts inside closed magnetic tubes in the corona. The alternation of condensations and rarefactions from the pressure modes drive large-amplitude pulsations in the plasma emission. Here we show the detection of such pulsations along magnetic tubes that brighten transiently in the hot 94 Å EUV channel of the Solar Dynamics Observatory/AIA. The pulsations are consistent with those predicted by hydrodynamic loop modeling, and confirm pulsed heating in the loop system. The comparison of observations and model provides constraints on the heat deposition: a good agreement requires loop twisting and pulses deposited close to the footpoints with a duration of 0.5 minutes in one loop, and deposited in the corona with a duration of 2.5 minutes in another loop of the same loop system.
Internal Dynamics and Stellar Content of Nine Ultra-diffuse Galaxies in the Coma Cluster Prove Their Evolutionary Link with Dwarf Early-type GalaxiesChilingarian, Igor V.Afanasiev, Anton V.Grishin, Kirill A.Fabricant, DanielMoran, Sean2019DOI: info:10.3847/1538-4357/ab4205The Astrophysical Journalv. 884 79 790004-637X
Chilingarian, Igor V., Afanasiev, Anton V., Grishin, Kirill A., Fabricant, Daniel, and Moran, Sean. 2019. "Internal Dynamics and Stellar Content of Nine Ultra-diffuse Galaxies in the Coma Cluster Prove Their Evolutionary Link with Dwarf Early-type Galaxies." The Astrophysical Journal 884: 79. https://doi.org/10.3847/1538-4357/ab4205
ID: 154712
Type: article
Authors: Chilingarian, Igor V.; Afanasiev, Anton V.; Grishin, Kirill A.; Fabricant, Daniel; Moran, Sean
Keywords: SAO
Abstract: Ultra-diffuse galaxies (UDGs) are spatially extended, low surface brightness stellar systems with regular elliptical-like morphology found in a wide range of environments. Studies of the internal dynamics and dark matter content of UDGs that would elucidate their formation and evolution have been hampered by their low surface brightnesses. Here, we present spatially resolved velocity profiles, stellar velocity dispersions, ages, and metallicities for nine UDGs in the Coma cluster. We use intermediate-resolution spectra obtained with Binospec, the MMT's new high-throughput optical spectrograph. We derive dark matter fractions between 50% and 90% within the half-light radius using Jeans dynamical models. Three galaxies exhibit major axis rotation, two others have highly anisotropic stellar orbits, and one shows signs of triaxiality. In the Faber-Jackson and mass-metallicity relations, the nine UDGs fill the gap between cluster dwarf elliptical (dE) and fainter dwarf spheroidal galaxies. Overall, the observed properties of all nine UDGs can be explained by a combination of internal processes (supernovae feedback) and environmental effects (ram pressure stripping, interaction with neighbors). These observations suggest that UDGs and dEs are members of the same galaxy population. All galaxy spectra presented in this work and their best-fitting stellar population templates are available at the following permanent address: https://doi.org/10.5281/zenodo.3387745.
Prospects for Wideband VLBI Correlation in the CloudGill, AjayBlackburn, LindyRoshanineshat, ArashChan, Chi-kwanDoeleman, Sheperd S.Johnson, Michael D.Raymond, Alexander W.Weintroub, Jonathan2019DOI: info:10.1088/1538-3873/ab32a8Publications of the Astronomical Society of the Pacificv. 131 124501 1245010004-6280
Gill, Ajay, Blackburn, Lindy, Roshanineshat, Arash, Chan, Chi-kwan, Doeleman, Sheperd S., Johnson, Michael D., Raymond, Alexander W., and Weintroub, Jonathan. 2019. "Prospects for Wideband VLBI Correlation in the Cloud." Publications of the Astronomical Society of the Pacific 131: 124501. https://doi.org/10.1088/1538-3873/ab32a8
ID: 154713
Type: article
Authors: Gill, Ajay; Blackburn, Lindy; Roshanineshat, Arash; Chan, Chi-kwan; Doeleman, Sheperd S.; Johnson, Michael D.; Raymond, Alexander W.; Weintroub, Jonathan
Keywords: SAO
Abstract: This paper proposes a cloud architecture for the correlation of wide bandwidth Very Long Baseline Interferometry (VLBI) data. Cloud correlation facilitates processing of entire experiments in parallel using flexibly allocated and practically unlimited compute resources. This approach offers a potential improvement over dedicated correlation clusters, which are constrained by a fixed number of installed processor nodes and playback units. Additionally, cloud storage offers an alternative to maintaining a fleet of hard disk drives that might be utilized intermittently. Here, we describe benchmarks of VLBI correlation using the DiFX-2.5.2 software on the Google Cloud Platform to assess cloud-based correlation performance. In our analysis, the number of virtual central processing units per virtual machine was varied to determine the optimum configuration of cloud resources. The number of stations was varied to determine the scaling of correlation time with VLBI arrays of different sizes. Data transfer rates from Google cloud storage to the virtual machines performing the correlation were also measured. Based on the results, we present an example cloud correlation configuration. Current cloud service and equipment pricing data is used to compile cost estimates allowing an approximate economic comparison between cloud and cluster processing. We note that the economic comparisons are based on cost figures which are a moving target, and are highly dependent on factors such as the utilization of cluster and media, which are a challenge to estimate. Our model suggests that shifting to the cloud is an alternative path for high data rate, low duty cycle wideband VLBI correlation that should continue to be explored. In the production phase of VLBI correlation, the cloud has the potential to significantly reduce data processing times and allow the processing of more science experiments in a given year for the petabyte- scale data sets increasingly common in both astronomy and geodesy VLBI applications.
The complete local volume groups sample - III. Characteristics of group central radio galaxies in the Local UniverseKolokythas, KonstantinosO'Sullivan, EwanIntema, HuibRaychaudhury, SomakBabul, ArifGiacintucci, SimonaGitti, Myriam2019DOI: info:10.1093/mnras/stz2082Monthly Notices of the Royal Astronomical Societyv. 489 2488 25042488–25040035-8711
Kolokythas, Konstantinos, O'Sullivan, Ewan, Intema, Huib, Raychaudhury, Somak, Babul, Arif, Giacintucci, Simona, and Gitti, Myriam. 2019. "The complete local volume groups sample - III. Characteristics of group central radio galaxies in the Local Universe." Monthly Notices of the Royal Astronomical Society 489: 2488– 2504. https://doi.org/10.1093/mnras/stz2082
ID: 154714
Type: article
Authors: Kolokythas, Konstantinos; O'Sullivan, Ewan; Intema, Huib; Raychaudhury, Somak; Babul, Arif; Giacintucci, Simona; Gitti, Myriam
Keywords: SAO
Abstract: Using new 610 and 235 MHz observations from the giant metrewave radio telescope (GMRT) in combination with archival GMRT and very large array (VLA) survey data, we present the radio properties of the dominant early-type galaxies in the low-richness subsample of the complete local-volume groups sample (CLoGS; 27 galaxy groups) and provide results for the radio properties of the full CLoGS sample for the first time. We find a high radio detection rate in the dominant galaxies of the low-richness subsample of 82 per cent (22/27); for the full CLoGS sample the detection rate is 87 per cent (46/53). The group-dominant galaxies exhibit a wide range of radio power, 1020-1025 W Hz-1 in the 235 and 610 MHz bands, with the majority (53 per cent) presenting point-like radio emission, 19 per cent hosting currently active radio jets, 6 per cent having remnant jets, 9 per cent being diffuse, and 13 per cent having no detected radio emission. The mean spectral index of the detected radio sources in the 235-610 MHz frequency range is found to be α _{235}^{610}̃0.68, and α _{235}^{1400}̃0.59 in the 235-1400 MHz one. In agreement with earlier studies, we find that the fraction of ultrasteep spectrum sources (α > 1.3) is ̃4 per cent, mostly dependent on the detection limit at 235 MHz. The majority of point-like systems are found to reside in dynamically young groups, whereas jet systems show no preference between spiral-rich and spiral-poor group environments. The mechanical power of the jet sources in the low-richness sample groups is estimated to be ̃1042-1044 erg s-1 with their black hole masses ranging between 2 × 108 and 5 × 109 M. We confirm previous findings that while radio jet sources tend to be associated with more massive black holes, black hole mass is not the decisive factor in determining jet activity or power.
Producing a BOSS CMASS sample with DES imagingLee, S.Huff, E. M.Ross, A. J.Choi, A.Hirata, C.Honscheid, K.MacCrann, N.Troxel, M. A.Davis, C.Eifler, T. F.Cawthon, R.Elvin-Poole, J.Annis, J.Avila, S.Bertin, E.Brooks, D.Carnero Rosell, A.Carrasco Kind, M.Carretero, J.da Costa, L. N.De Vicente, J.Desai, S.Flaugher, B.Fosalba, P.García-Bellido, J.Gaztanaga, E.Gerdes, D. W.Gruen, D.Gruendl, R. A.Gschwend, J.Gutierrez, G.Hollowood, D. L.James, David J.Jeltema, T.Kuehn, K.Lima, M.Maia, M. A. G.Marshall, J. L.Martini, P.Melchior, P.Menanteau, F.Miller, C. J.Miquel, R.Ogando, R. L. C.Palmese, A.Plazas, A. A.Sanchez, E.Scarpine, V.Schubnell, M.Serrano, S.Sevilla-Noarbe, I.Smith, M.Soares-Santos, M.Sobreira, F.Suchyta, E.Swanson, M. E. C.Tarle, G.Thomas, D.Weller, J.Zuntz, J.2019DOI: info:10.1093/mnras/stz2288Monthly Notices of the Royal Astronomical Societyv. 489 2887 29062887–29060035-8711
Lee, S., Huff, E. M., Ross, A. J., Choi, A., Hirata, C., Honscheid, K., MacCrann, N., Troxel, M. A., Davis, C., Eifler, T. F., Cawthon, R., Elvin-Poole, J., Annis, J., Avila, S., Bertin, E., Brooks, D., Carnero Rosell, A., Carrasco Kind, M., Carretero, J., da Costa, L. N., De Vicente, J., Desai, S., Flaugher, B., Fosalba, P., García-Bellido, J. et al. 2019. "Producing a BOSS CMASS sample with DES imaging." Monthly Notices of the Royal Astronomical Society 489: 2887– 2906. https://doi.org/10.1093/mnras/stz2288
ID: 154715
Type: article
Authors: Lee, S.; Huff, E. M.; Ross, A. J.; Choi, A.; Hirata, C.; Honscheid, K.; MacCrann, N.; Troxel, M. A.; Davis, C.; Eifler, T. F.; Cawthon, R.; Elvin-Poole, J.; Annis, J.; Avila, S.; Bertin, E.; Brooks, D.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; da Costa, L. N.; De Vicente, J.; Desai, S.; Flaugher, B.; Fosalba, P.; García-Bellido, J.; Gaztanaga, E.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Hollowood, D. L.; James, David J.; Jeltema, T.; Kuehn, K.; Lima, M.; Maia, M. A. G.; Marshall, J. L.; Martini, P.; Melchior, P.; Menanteau, F.; Miller, C. J.; Miquel, R.; Ogando, R. L. C.; Palmese, A.; Plazas, A. A.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Serrano, S.; Sevilla-Noarbe, I.; Smith, M.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Weller, J.; Zuntz, J.
Keywords: SAO
Abstract: We present a sample of galaxies with the Dark Energy Survey (DES) photometry that replicates the properties of the BOSS CMASS sample. The CMASS galaxy sample has been well characterized by the Sloan Digital Sky Survey (SDSS) collaboration and was used to obtain the most powerful redshift-space galaxy clustering measurements to date. A joint analysis of redshift-space distortions (such as those probed by CMASS from SDSS) and a galaxy-galaxy lensing measurement for an equivalent sample from DES can provide powerful cosmological constraints. Unfortunately, the DES and SDSS-BOSS footprints have only minimal overlap, primarily on the celestial equator near the SDSS Stripe 82 region. Using this overlap, we build a robust Bayesian model to select CMASS-like galaxies in the remainder of the DES footprint. The newly defined DES-CMASS (DMASS) sample consists of 117 293 effective galaxies covering 1244 \deg ^2. Through various validation tests, we show that the DMASS sample selected by this model matches well with the BOSS CMASS sample, specifically in the South Galactic cap (SGC) region that includes Stripe 82. Combining measurements of the angular correlation function and the clustering-z distribution of DMASS, we constrain the difference in mean galaxy bias and mean redshift between the BOSS CMASS and DMASS samples to be ∆ b = 0.010^{+0.045}_{-0.052} and ∆ z = \left(3.46^{+5.48}_{-5.55} \right) × 10^{-3} for the SGC portion of CMASS, and ∆ b = 0.044^{+0.044}_{-0.043} and ∆ z= (3.51^{+4.93}_{-5.91}) × 10^{-3} for the full CMASS sample. These values indicate that the mean bias of galaxies and mean redshift in the DMASS sample are consistent with both CMASS samples within 1σ.
An Ideal Testbed for Planet-Disk Interaction: Two Giant Protoplanets in Resonance Shaping the PDS 70 Protoplanetary DiskBae, JaehanZhu, ZhaohuanBaruteau, ClémentBenisty, MyriamDullemond, Cornelis P.Facchini, StefanoIsella, AndreaKeppler, MiriamPérez, Laura M.Teague, Richard2019DOI: info:10.3847/2041-8213/ab46b0The Astrophysical Journalv. 884 L41 L410004-637X
Bae, Jaehan, Zhu, Zhaohuan, Baruteau, Clément, Benisty, Myriam, Dullemond, Cornelis P., Facchini, Stefano, Isella, Andrea, Keppler, Miriam, Pérez, Laura M., and Teague, Richard. 2019. "An Ideal Testbed for Planet-Disk Interaction: Two Giant Protoplanets in Resonance Shaping the PDS 70 Protoplanetary Disk." The Astrophysical Journal 884: L41. https://doi.org/10.3847/2041-8213/ab46b0
ID: 154716
Type: article
Authors: Bae, Jaehan; Zhu, Zhaohuan; Baruteau, Clément; Benisty, Myriam; Dullemond, Cornelis P.; Facchini, Stefano; Isella, Andrea; Keppler, Miriam; Pérez, Laura M.; Teague, Richard
Keywords: SAO
Abstract: While numerical simulations have been playing a key role in the studies of planet-disk interaction, testing numerical results against observations has been limited so far. With the two directly imaged protoplanets embedded in its circumstellar disk, PDS 70 offers an ideal testbed for planet-disk interaction studies. Using two-dimensional hydrodynamic simulations we show that the observed features can be well explained with the two planets in formation, providing strong evidence that previously proposed theories of planet-disk interaction are in action, including resonant migration, particle trapping, size segregation, and filtration. Our simulations suggest that the two planets are likely in 2:1 mean motion resonance and can remain dynamically stable over million-year timescales. The growth of the planets at 10-8-10-7 M Jup yr-1, rates comparable to the estimates from Hα observations, does not destabilize the resonant configuration. Large grains are filtered at the gap edge and only small, (sub-)μm grains can flow to the circumplanetary disks (CPDs) and the inner circumstellar disk. With the submillimeter continuum ring observed outward of the two directly imaged planets, PDS 70 provides the first observational evidence of particle filtration by gap-opening planets. The observed submillimeter continuum emission at the vicinity of the planets can be reproduced when (sub-)μm grains survive over multiple CPD gas viscous timescales and accumulate therein. One such possibility is if (sub-)μm grains grow in size and remain trapped in pressure bumps, similar to what we find happening in circumstellar disks. We discuss potential implications to planet formation in the solar system and mature extrasolar planetary systems.
Modelling the AGN broad line region using single-epoch spectra - I. The test case of Arp 151Raimundo, S. I.Pancoast, AnnaVestergaard, M.Goad, M. R.Barth, A. J.2019DOI: info:10.1093/mnras/stz2243Monthly Notices of the Royal Astronomical Societyv. 489 1899 19181899–19180035-8711
Raimundo, S. I., Pancoast, Anna, Vestergaard, M., Goad, M. R., and Barth, A. J. 2019. "Modelling the AGN broad line region using single-epoch spectra - I. The test case of Arp 151." Monthly Notices of the Royal Astronomical Society 489: 1899– 1918. https://doi.org/10.1093/mnras/stz2243
ID: 154717
Type: article
Authors: Raimundo, S. I.; Pancoast, Anna; Vestergaard, M.; Goad, M. R.; Barth, A. J.
Keywords: SAO
Abstract: We show that individual (single-epoch) spectra of active galactic nuclei (AGNs) can constrain some of the geometry and dynamics of the AGN broad line region. Studies of the cosmic influence of supermassive black holes are limited by the current large uncertainties in the determination of black hole masses. One dominant limitation is the unknown geometry, dynamics, and line-of-sight inclination of the broad line region, used to probe the central black hole mass. Recent progress has been made to constrain the spatial and kinematic structure of the broad line region using dynamical modelling of AGN monitoring data and an underlying physical model for the broad line region. In this work we test the ability of a modified version of this dynamical modelling code to constrain the broad line region structure using single-epoch spectra. We test our modelling code on single-epoch spectra of nearby Arp 151 by comparing our results with those obtained with monitoring data of this same object. We find that a significant fraction of the broad line region parameters can indeed be adequately constrained, with uncertainties that are comparable to, or at most a factor of approximately a few higher than those obtained from modelling of monitoring data. Considering the wealth of available single-epoch spectroscopic observations, this method is promising for establishing the overall AGN population trends in the geometry and dynamics of the broad line region. This method can be applied to spectra of AGNs at low and high redshift making it valuable for studies of cosmological black hole and AGN evolution.
Two New HATNet Hot Jupiters around A Stars and the First Glimpse at the Occurrence Rate of Hot Jupiters from TESSZhou, GeorgeHuang, C. X.Bakos, G. Á.Hartman, J. D.Latham, David W.Quinn, Samuel N.Collins, Karen A.Winn, J. N.Wong, I.Kovács, G.Csubry, Z.Bhatti, W.Penev, K.Bieryla, AllysonEsquerdo, Gilbert A.Berlind, PerryCalkins, Michael L.de Val-Borro, M.Noyes, R. W.Lázár, J.Papp, I.Sári, P.Kovács, T.Buchhave, Lars A.Szklenar, T.Béky, B.Johnson, M. C.Cochran, W. D.Kniazev, A. Y.Stassun, K. G.Fulton, B. J.Shporer, A.Espinoza, N.Bayliss, D.Everett, M.Howell, S. B.Hellier, C.Anderson, D. R.Collier Cameron, A.West, R. G.Brown, D. J. A.Schanche, N.Barkaoui, K.Pozuelos, F.Gillon, M.Jehin, E.Benkhaldoun, Z.Daassou, A.Ricker, G.Vanderspek, R.Seager, S.Jenkins, J. M.Lissauer, Jack J.Armstrong, J. D.Collins, K. I.Gan, T.Hart, R.Horne, K.Kielkopf, J. F.Nielsen, L. D.Nishiumi, T.Narita, N.Palle, E.Relles, Howard M.Sefako, R.Tan, T. G.Davies, M.Goeke, Robert F.Guerrero, N.Haworth, K.Villanueva, S.2019DOI: info:10.3847/1538-3881/ab36b5The Astronomical Journalv. 158 141 1410004-6256
Zhou, George, Huang, C. X., Bakos, G. Á., Hartman, J. D., Latham, David W., Quinn, Samuel N., Collins, Karen A., Winn, J. N., Wong, I., Kovács, G., Csubry, Z., Bhatti, W., Penev, K., Bieryla, Allyson, Esquerdo, Gilbert A., Berlind, Perry, Calkins, Michael L., de Val-Borro, M., Noyes, R. W., Lázár, J., Papp, I., Sári, P., Kovács, T., Buchhave, Lars A., Szklenar, T. et al. 2019. "Two New HATNet Hot Jupiters around A Stars and the First Glimpse at the Occurrence Rate of Hot Jupiters from TESS." The Astronomical Journal 158: 141. https://doi.org/10.3847/1538-3881/ab36b5
ID: 154718
Type: article
Authors: Zhou, George; Huang, C. X.; Bakos, G. Á.; Hartman, J. D.; Latham, David W.; Quinn, Samuel N.; Collins, Karen A.; Winn, J. N.; Wong, I.; Kovács, G.; Csubry, Z.; Bhatti, W.; Penev, K.; Bieryla, Allyson; Esquerdo, Gilbert A.; Berlind, Perry; Calkins, Michael L.; de Val-Borro, M.; Noyes, R. W.; Lázár, J.; Papp, I.; Sári, P.; Kovács, T.; Buchhave, Lars A.; Szklenar, T.; Béky, B.; Johnson, M. C.; Cochran, W. D.; Kniazev, A. Y.; Stassun, K. G.; Fulton, B. J.; Shporer, A.; Espinoza, N.; Bayliss, D.; Everett, M.; Howell, S. B.; Hellier, C.; Anderson, D. R.; Collier Cameron, A.; West, R. G.; Brown, D. J. A.; Schanche, N.; Barkaoui, K.; Pozuelos, F.; Gillon, M.; Jehin, E.; Benkhaldoun, Z.; Daassou, A.; Ricker, G.; Vanderspek, R.; Seager, S.; Jenkins, J. M.; Lissauer, Jack J.; Armstrong, J. D.; Collins, K. I.; Gan, T.; Hart, R.; Horne, K.; Kielkopf, J. F.; Nielsen, L. D.; Nishiumi, T.; Narita, N.; Palle, E.; Relles, Howard M.; Sefako, R.; Tan, T. G.; Davies, M.; Goeke, Robert F.; Guerrero, N.; Haworth, K.; Villanueva, S.
Keywords: SAO
Abstract: Wide-field surveys for transiting planets are well suited to searching diverse stellar populations, enabling a better understanding of the link between the properties of planets and their parent stars. We report the discovery of HAT-P-69 b (TOI 625.01) and HAT-P-70 b (TOI 624.01), two new hot Jupiters around A stars from the Hungarian-made Automated Telescope Network (HATNet) survey that have also been observed by the Transiting Exoplanet Survey Satellite. HAT-P-69 b has a mass of {3.58}-0.58+0.58 M Jup and a radius of {1.676}-0.033+0.051 R Jup and resides in a prograde 4.79 day orbit. HAT-P-70 b has a radius of {1.87}-0.10+0.15 R Jup and a mass constraint of and a mass constraint of Jup and resides in a retrograde 2.74 day orbit. We use the confirmation of these planets around relatively massive stars as an opportunity to explore the occurrence rate of hot Jupiters as a function of stellar mass. We define a sample of 47,126 main-sequence stars brighter than T mag = 10 that yields 31 giant planet candidates, including 18 confirmed planets, 3 candidates, and 10 false positives. We find a net hot Jupiter occurrence rate of 0.41 ± 0.10% within this sample, consistent with the rate measured by Kepler for FGK stars. When divided into stellar mass bins, we find the occurrence rate to be 0.71 ± 0.31% for G stars, 0.43 ± 0.15% for F stars, and 0.26 ± 0.11% for A stars. Thus, at this point, we cannot discern any statistically significant trend in the occurrence of hot Jupiters with stellar mass. Based on observations obtained with the Hungarian-made Automated Telescope Network. Based in part on observations obtained with the Tillinghast Reflector 1.5 m telescope and the 1.2 m telescope, both operated by the Smithsonian Astrophysical Observatory at the Fred Lawrence Whipple Observatory in Arizona. This work makes use of the Smithsonian Institution High Performance Cluster (SI/HPC). Based in part on observations made with the Southern African Large Telescope (SALT).
First Hard X-Ray Observation of a Compact Symmetric Object: A Broadband X-Ray Study of a Radio Galaxy OQ+208 with NuSTAR and ChandraSobolewska, MałgosiaSiemiginowska, AnetaGuainazzi, MatteoHardcastle, MartinMigliori, GiuliaOstorero, LuisaStawarz, Łukasz2019DOI: info:10.3847/1538-4357/ab3ec3The Astrophysical Journalv. 884 166 1660004-637X
Sobolewska, Małgosia, Siemiginowska, Aneta, Guainazzi, Matteo, Hardcastle, Martin, Migliori, Giulia, Ostorero, Luisa, and Stawarz, Łukasz. 2019. "First Hard X-Ray Observation of a Compact Symmetric Object: A Broadband X-Ray Study of a Radio Galaxy OQ+208 with NuSTAR and Chandra." The Astrophysical Journal 884: 166. https://doi.org/10.3847/1538-4357/ab3ec3
ID: 154719
Type: article
Authors: Sobolewska, Małgosia; Siemiginowska, Aneta; Guainazzi, Matteo; Hardcastle, Martin; Migliori, Giulia; Ostorero, Luisa; Stawarz, Łukasz
Keywords: SAO
Abstract: Compact symmetric objects (CSOs) have been observed with Chandra and XMM-Newton to gain insights into the initial stages of a radio source evolution and to probe the black hole activity at the time of relativistic outflow formation. However, there have been no CSO observations to date at the hard X-ray energies (>10 keV), impeding our ability to robustly constrain the properties of the intrinsic X-ray emission and of the medium surrounding the young expanding jets. We present the first hard X-ray observation of a CSO performed with the Nuclear Spectroscopic Telescope Array (NuSTAR). Our target, OQ +208, is detected up to 30 keV, and thus we establish CSOs as a new class of the NuSTAR sources. We analyze the NuSTAR data jointly with our new Chandra and archival XMM-Newton data and find that a young (̃250 yr old) radio jet spanning the length of 10 pc coexists with cold obscuring matter, consistent with a dusty torus, with an equivalent hydrogen column density of N H = 1023-1024 cm-2. The primary X-ray emission is characterized by a photon index of Γ ̃ 1.45 and an intrinsic 0.5-30 keV luminosity of L ≃ 1043 erg s-1. The results of our spectral modeling and broad-line optical classification of the source suggest a porous structure of the obscuring torus. Alternatively, the source may belong to the class of optically unobscured/X-ray-obscured active galactic nucleus. The observed X-ray emission is too weak compared to that predicted by the expanding radio lobes model, leaving an accretion disk corona or jets as the possible origins of the X-ray emission from this young radio galaxy.
RELICS: Reionization Lensing Cluster SurveyCoe, DanSalmon, BrettBradač, MarušaBradley, Larry D.Sharon, KerenZitrin, AdiAcebron, AnaCerny, CatherineCibirka, NatháliaStrait, VictoriaPaterno-Mahler, RachelMahler, GuillaumeAvila, Roberto J.Ogaz, SaraHuang, Kuang-HanPelliccia, DeboraStark, Daniel P.Mainali, RameshOesch, Pascal A.Trenti, MicheleCarrasco, DanielaDawson, William A.Rodney, Steven A.Strolger, Louis-GregoryRiess, Adam G.Jones, ChristineFrye, Brenda L.Czakon, Nicole G.Umetsu, KeiichiVulcani, BenedettaGraur, OrJha, Saurabh W.Graham, Melissa L.Molino, AlbertoNonino, MarioHjorth, JensSelsing, JonatanChristensen, LiseKikuchihara, ShotaroOuchi, MasamiOguri, MasamuneWelch, BrianLemaux, Brian C.Andrade-Santos, FelipeHoag, Austin T.Johnson, Traci L.Peterson, AveryPast, MatthewFox, CarterAgulli, IreneLivermore, RachaelRyan, Russell E.Lam, DanielSendra-Server, IreneToft, SuneLovisari, LorenzoSu, Yuanyuan2019DOI: info:10.3847/1538-4357/ab412bThe Astrophysical Journalv. 884 85 850004-637X
Coe, Dan, Salmon, Brett, Bradač, Maruša, Bradley, Larry D., Sharon, Keren, Zitrin, Adi, Acebron, Ana, Cerny, Catherine, Cibirka, Nathália, Strait, Victoria, Paterno-Mahler, Rachel, Mahler, Guillaume, Avila, Roberto J., Ogaz, Sara, Huang, Kuang-Han, Pelliccia, Debora, Stark, Daniel P., Mainali, Ramesh, Oesch, Pascal A., Trenti, Michele, Carrasco, Daniela, Dawson, William A., Rodney, Steven A., Strolger, Louis-Gregory, Riess, Adam G. et al. 2019. "RELICS: Reionization Lensing Cluster Survey." The Astrophysical Journal 884: 85. https://doi.org/10.3847/1538-4357/ab412b
ID: 154720
Type: article
Authors: Coe, Dan; Salmon, Brett; Bradač, Maruša; Bradley, Larry D.; Sharon, Keren; Zitrin, Adi; Acebron, Ana; Cerny, Catherine; Cibirka, Nathália; Strait, Victoria; Paterno-Mahler, Rachel; Mahler, Guillaume; Avila, Roberto J.; Ogaz, Sara; Huang, Kuang-Han; Pelliccia, Debora; Stark, Daniel P.; Mainali, Ramesh; Oesch, Pascal A.; Trenti, Michele; Carrasco, Daniela; Dawson, William A.; Rodney, Steven A.; Strolger, Louis-Gregory; Riess, Adam G.; Jones, Christine; Frye, Brenda L.; Czakon, Nicole G.; Umetsu, Keiichi; Vulcani, Benedetta; Graur, Or; Jha, Saurabh W.; Graham, Melissa L.; Molino, Alberto; Nonino, Mario; Hjorth, Jens; Selsing, Jonatan; Christensen, Lise; Kikuchihara, Shotaro; Ouchi, Masami; Oguri, Masamune; Welch, Brian; Lemaux, Brian C.; Andrade-Santos, Felipe; Hoag, Austin T.; Johnson, Traci L.; Peterson, Avery; Past, Matthew; Fox, Carter; Agulli, Irene; Livermore, Rachael; Ryan, Russell E.; Lam, Daniel; Sendra-Server, Irene; Toft, Sune; Lovisari, Lorenzo; Su, Yuanyuan
Keywords: SAO
Abstract: Large surveys of galaxy clusters with the Hubble Space Telescope (HST) and Spitzer, including the Cluster Lensing And Supernova survey with Hubble and the Frontier Fields, have demonstrated the power of strong gravitational lensing to efficiently deliver large samples of high- redshift galaxies. We extend this strategy through a wider, shallower survey named RELICS, the Reionization Lensing Cluster Survey, described here. Our 188-orbit Hubble Treasury Program observed 41 clusters at 0.182 ≤ z ≤ 0.972 with Advanced Camera for Surveys (ACS) and WFC3/IR imaging spanning 0.4-1.7 μm. We selected 21 of the most massive clusters known based on Planck PSZ2 estimates and 20 additional clusters based on observed or inferred lensing strength. RELICS observed 46 WFC3/IR pointings (̃200 arcmin2) each with two orbits divided among four filters (F105W, F125W, F140W, and F160W) and ACS imaging as needed to achieve single-orbit depth in each of three filters (F435W, F606W, and F814W). As previously reported by Salmon et al., we discovered over 300 z ̃ 6-10 candidates, including the brightest z ̃ 6 candidates known, and the most distant spatially resolved lensed arc known at z ̃ 10. Spitzer IRAC imaging (945 hr awarded, plus 100 archival, spanning 3.0-5.0 μm) has crucially enabled us to distinguish z ̃ 10 candidates from z ̃ 2 interlopers. For each cluster, two HST observing epochs were staggered by about a month, enabling us to discover 11 supernovae, including 3 lensed supernovae, which we followed up with 20 orbits from our program. Reduced HST images, catalogs, and lens models are available on MAST, and reduced Spitzer images are available on IRSA.
The Revised TESS Input Catalog and Candidate Target ListStassun, Keivan G.Oelkers, Ryan J.Paegert, MartinTorres, GuillermoPepper, JoshuaDe Lee, NathanCollins, KevinLatham, David W.Muirhead, Philip S.Chittidi, JayRojas-Ayala, BárbaraFleming, Scott W.Rose, Mark E.Tenenbaum, PeterTing, Eric B.Kane, Stephen R.Barclay, ThomasBean, Jacob L.Brassuer, C. E.Charbonneau, DavidGe, JianLissauer, Jack J.Mann, Andrew W.McLean, BrianMullally, SusanNarita, NorioPlavchan, PeterRicker, George R.Sasselov, DimitarSeager, S.Sharma, SanjibShiao, BernieSozzetti, AlessandroStello, DennisVanderspek, RolandWallace, GeoffWinn, Joshua N.2019DOI: info:10.3847/1538-3881/ab3467The Astronomical Journalv. 158 138 1380004-6256
Stassun, Keivan G., Oelkers, Ryan J., Paegert, Martin, Torres, Guillermo, Pepper, Joshua, De Lee, Nathan, Collins, Kevin, Latham, David W., Muirhead, Philip S., Chittidi, Jay, Rojas-Ayala, Bárbara, Fleming, Scott W., Rose, Mark E., Tenenbaum, Peter, Ting, Eric B., Kane, Stephen R., Barclay, Thomas, Bean, Jacob L., Brassuer, C. E., Charbonneau, David, Ge, Jian, Lissauer, Jack J., Mann, Andrew W., McLean, Brian, Mullally, Susan et al. 2019. "The Revised TESS Input Catalog and Candidate Target List." The Astronomical Journal 158: 138. https://doi.org/10.3847/1538-3881/ab3467
ID: 154721
Type: article
Authors: Stassun, Keivan G.; Oelkers, Ryan J.; Paegert, Martin; Torres, Guillermo; Pepper, Joshua; De Lee, Nathan; Collins, Kevin; Latham, David W.; Muirhead, Philip S.; Chittidi, Jay; Rojas-Ayala, Bárbara; Fleming, Scott W.; Rose, Mark E.; Tenenbaum, Peter; Ting, Eric B.; Kane, Stephen R.; Barclay, Thomas; Bean, Jacob L.; Brassuer, C. E.; Charbonneau, David; Ge, Jian; Lissauer, Jack J.; Mann, Andrew W.; McLean, Brian; Mullally, Susan; Narita, Norio; Plavchan, Peter; Ricker, George R.; Sasselov, Dimitar; Seager, S.; Sharma, Sanjib; Shiao, Bernie; Sozzetti, Alessandro; Stello, Dennis; Vanderspek, Roland; Wallace, Geoff; Winn, Joshua N.
Keywords: SAO
Abstract: We describe the catalogs assembled and the algorithms used to populate the revised TESS Input Catalog (TIC), based on the incorporation of the Gaia second data release. We also describe a revised ranking system for prioritizing stars for 2 minute cadence observations, and we assemble a revised Candidate Target List (CTL) using that ranking. The TIC is available on the Mikulski Archive for Space Telescopes server, and an enhanced CTL is available through the Filtergraph data visualization portal system at ht tp://filtergraph.vanderbilt.edu/tess_ctl.
VIS3COS. II. Nature and nurture in galaxy structure and morphologyPaulino-Afonso, AnaSobral, DavidDarvish, BehnamRibeiro, Brunovan der Wel, ArjenStott, JohnBuitrago, FernandoBest, PhilipStroe, AndraCraig, Jessica E. M.2019DOI: info:10.1051/0004-6361/201935137Astronomy and Astrophysicsv. 630 A57 A570004-6361
Paulino-Afonso, Ana, Sobral, David, Darvish, Behnam, Ribeiro, Bruno, van der Wel, Arjen, Stott, John, Buitrago, Fernando, Best, Philip, Stroe, Andra, and Craig, Jessica E. M. 2019. "VIS3COS. II. Nature and nurture in galaxy structure and morphology." Astronomy and Astrophysics 630: A57. https://doi.org/10.1051/0004-6361/201935137
ID: 154722
Type: article
Authors: Paulino-Afonso, Ana; Sobral, David; Darvish, Behnam; Ribeiro, Bruno; van der Wel, Arjen; Stott, John; Buitrago, Fernando; Best, Philip; Stroe, Andra; Craig, Jessica E. M.
Keywords: SAO
Abstract: We study the impact of local density and stellar mass on the structure and morphology of approximately 500 quiescent and star-forming galaxies from the VIMOS Spectroscopic Survey of a Superstructure in COSMOS (VIS3COS). We perform bulge-to-disc decomposition of the surface brightness profiles and find ̃41 ± 3% of > 1010 M galaxies to be best fitted with two components. We complement our analysis with non-parametric morphological measurements and qualitative visual classifications. We find that both galaxy structure and morphology depend on stellar mass and environment for our sample as a whole. We only find an impact of the environment on galaxy size for galaxies more massive than 1011 M. We find higher Sérsic indices (n) and bulge-to-total ratios (B/T) in high- density regions when compared to low-density counterparts at similar stellar masses. We also find that galaxies with higher stellar mass have steeper light profiles (high n, B/T) compared to galaxies with lower stellar mass. Using visual classifications, we find a morphology-density relation at z ̃ 0.84 for galaxies more massive than 1010 M, with elliptical galaxies being dominant at high-density regions and disc galaxies more common in low-density regions. However, when splitting the sample into colour-colour-selected star-forming and quiescent sub-populations, there are no statistically significant differences between low- and high-density regions. We find that quiescent galaxies are smaller, have higher Sérsic indices (for single profiles, around n ̃ 4), and higher bulge-to-total light ratios (for decomposed profiles, around B/T ̃ 0.5) when compared to star-forming counterparts (n ̃ 1 and B/T ̃ 0.3, for single and double profiles, respectively). We confirm these trends with non-parametric quantities, finding quiescent galaxies to be smoother (lower asymmetry, lower M20) and to have most of their light over smaller areas (higher concentration and Gini coefficient) than star-forming galaxies. Overall, we find a stronger dependence of structure and morphology on stellar mass than on local density and these relations are strongly correlated with the quenching fraction. The change in average structure or morphology corresponds to a change in the relative fractions of blue disc-like galaxies and red elliptical galaxies with stellar mass and environment. We hypothesise that the processes responsible for the quenching of star formation must also affect the galaxy morphology on similar timescales.
Spiral Structure in the Gas Disk of TW HyaTeague, RichardBae, JaehanHuang, JaneBergin, Edwin A.2019DOI: info:10.3847/2041-8213/ab4a83The Astrophysical Journalv. 884 L56 L560004-637X
Teague, Richard, Bae, Jaehan, Huang, Jane, and Bergin, Edwin A. 2019. "Spiral Structure in the Gas Disk of TW Hya." The Astrophysical Journal 884: L56. https://doi.org/10.3847/2041-8213/ab4a83
ID: 154723
Type: article
Authors: Teague, Richard; Bae, Jaehan; Huang, Jane; Bergin, Edwin A.
Keywords: SAO
Abstract: We report the detection of spiral substructure in both the gas velocity and temperature structure of the disk around TW Hya, suggestive of planet-disk interactions with an unseen planet. Perturbations from Keplerian rotation tracing out a spiral pattern are observed in the SE of the disk, while significant azimuthal perturbations in the gas temperature are seen in the outer disk, outside 90 au, extending the full azimuth of the disk. The deviation in velocity is either ∆v ϕ /v kep ̃ 0.1 or ∆v z /v kep ̃ 0.01 depending on whether the perturbation is in the rotational or vertical direction, while radial perturbations can be ruled out. Deviations in the gas temperature are ±4 K about the azimuthally averaged profile, equivalent to deviations of ∆T gas/T gas ̃ 0.05. Assuming all three structures can be described by an Archimedean spiral, measurements of the pitch angles of both velocity and temperature spirals show a radially decreasing trend for all three, ranging from 9° at 70 au, dropping to 3° at 200 au. Such low pitch- angled spirals are not readily explained through the wake of an embedded planet in the location of previously reported at 94 au, but rather require a launching mechanism that results in much more tightly wound spirals. Molecular emission tracing distinct heights in the disk is required to accurately distinguish between spiral launching mechanisms.
Three Red Suns in the Sky: A Transiting, Terrestrial Planet in a Triple M-dwarf System at 6.9 pcWinters, Jennifer G.Medina, Amber A.Irwin, Jonathan M.Charbonneau, DavidAstudillo-Defru, NicolaHorch, Elliott P.Eastman, Jason D.Halley Vrijmoet, EliotHenry, Todd J.Diamond-Lowe, HannahWinston, ElaineBarclay, ThomasBonfils, XavierRicker, George R.Vanderspek, RolandLatham, David W.Seager, SaraWinn, Joshua N.Jenkins, Jon M.Udry, StéphaneTwicken, Joseph D.Teske, Johanna K.Tenenbaum, PeterPepe, FrancescoMurgas, FelipeMuirhead, Philip S.Mink, JessicaLovis, ChristopheLevine, Alan M.Lépine, SébastienJao, Wei-ChunHenze, Christopher E.Furész, GáborForveille, ThierryFigueira, PedroEsquerdo, Gilbert A.Dressing, Courtney D.Díaz, Rodrigo F.Delfosse, XavierBurke, Christopher J.Bouchy, FrançoisBerlind, PerryAlmenara, Jose-Manuel2019DOI: info:10.3847/1538-3881/ab364dThe Astronomical Journalv. 158 152 1520004-6256
Winters, Jennifer G., Medina, Amber A., Irwin, Jonathan M., Charbonneau, David, Astudillo-Defru, Nicola, Horch, Elliott P., Eastman, Jason D., Halley Vrijmoet, Eliot, Henry, Todd J., Diamond-Lowe, Hannah, Winston, Elaine, Barclay, Thomas, Bonfils, Xavier, Ricker, George R., Vanderspek, Roland, Latham, David W., Seager, Sara, Winn, Joshua N., Jenkins, Jon M., Udry, Stéphane, Twicken, Joseph D., Teske, Johanna K., Tenenbaum, Peter, Pepe, Francesco, Murgas, Felipe et al. 2019. "Three Red Suns in the Sky: A Transiting, Terrestrial Planet in a Triple M-dwarf System at 6.9 pc." The Astronomical Journal 158: 152. https://doi.org/10.3847/1538-3881/ab364d
ID: 154724
Type: article
Authors: Winters, Jennifer G.; Medina, Amber A.; Irwin, Jonathan M.; Charbonneau, David; Astudillo-Defru, Nicola; Horch, Elliott P.; Eastman, Jason D.; Halley Vrijmoet, Eliot; Henry, Todd J.; Diamond-Lowe, Hannah; Winston, Elaine; Barclay, Thomas; Bonfils, Xavier; Ricker, George R.; Vanderspek, Roland; Latham, David W.; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Udry, Stéphane; Twicken, Joseph D.; Teske, Johanna K.; Tenenbaum, Peter; Pepe, Francesco; Murgas, Felipe; Muirhead, Philip S.; Mink, Jessica; Lovis, Christophe; Levine, Alan M.; Lépine, Sébastien; Jao, Wei-Chun; Henze, Christopher E.; Furész, Gábor; Forveille, Thierry; Figueira, Pedro; Esquerdo, Gilbert A.; Dressing, Courtney D.; Díaz, Rodrigo F.; Delfosse, Xavier; Burke, Christopher J.; Bouchy, François; Berlind, Perry; Almenara, Jose-Manuel
Keywords: SAO
Abstract: We present the discovery from Transiting Exoplanet Survey Satellite (TESS) data of LTT 1445Ab. At a distance of 6.9 pc, it is the second nearest transiting exoplanet system found to date, and the closest one known for which the primary is an M dwarf. The host stellar system consists of three mid-to-late M dwarfs in a hierarchical configuration, which are blended in one TESS pixel. We use MEarth data and results from the Science Processing Operations Center data validation report to determine that the planet transits the primary star in the system. The planet has a radius of {1.38}-0.12+0.13 {R}\oplus , an orbital period of {5.35882}-0.00031+0.00030 days, and an equilibrium temperature of {433}-27+28 K. With radial velocities from the High Accuracy Radial Velocity Planet Searcher, we place a 3σ upper mass limit of 8.4 {M}\oplus on the planet. LTT 1445Ab provides one of the best opportunities to date for the spectroscopic study of the atmosphere of a terrestrial world. We also present a detailed characterization of the host stellar system. We use high-resolution spectroscopy and imaging to rule out the presence of any other close stellar or brown dwarf companions. Nineteen years of photometric monitoring of A and BC indicate a moderate amount of variability, in agreement with that observed in the TESS light-curve data. We derive a preliminary astrometric orbit for the BC pair that reveals an edge-on and eccentric configuration. The presence of a transiting planet in this system hints that the entire system may be co- planar, implying that the system may have formed from the early fragmentation of an individual protostellar core.
The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars. I. Identifying and Characterizing the Protostellar Content of the OMC-2 FIR4 and OMC-2 FIR3 RegionsTobin, John J.Megeath, S. Thomasvan't Hoff, MerelDíaz-Rodríguez, Ana KarlaReynolds, NickalasOsorio, MayraAnglada, GuillemFurlan, EliseKarnath, NicoleOffner, Stella S. R.Sheehan, Patrick D.Sadavoy, Sarah I.Stutz, Amelia M.Fischer, William J.Kama, MihkelPersson, Magnusdi Francesco, JamesLooney, Leslie W.Watson, Dan M.Li, Zhi-YunStephens, IanChandler, Claire J.Cox, ErinDunham, Michael M.Kratter, KaitlinKounkel, MarinaMazur, BrianMurillo, Nadia M.Patel, LisaPerez, LauraSegura-Cox, DominiqueSharma, RajeebTychoniec, ŁukaszWyrowski, Friedrich2019DOI: info:10.3847/1538-4357/ab498fThe Astrophysical Journalv. 886 6 60004-637X
Tobin, John J., Megeath, S. Thomas, van't Hoff, Merel, Díaz-Rodríguez, Ana Karla, Reynolds, Nickalas, Osorio, Mayra, Anglada, Guillem, Furlan, Elise, Karnath, Nicole, Offner, Stella S. R., Sheehan, Patrick D., Sadavoy, Sarah I., Stutz, Amelia M., Fischer, William J., Kama, Mihkel, Persson, Magnus, di Francesco, James, Looney, Leslie W., Watson, Dan M., Li, Zhi-Yun, Stephens, Ian, Chandler, Claire J., Cox, Erin, Dunham, Michael M., Kratter, Kaitlin et al. 2019. "The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars. I. Identifying and Characterizing the Protostellar Content of the OMC-2 FIR4 and OMC-2 FIR3 Regions." The Astrophysical Journal 886: 6. https://doi.org/10.3847/1538-4357/ab498f
ID: 154585
Type: article
Authors: Tobin, John J.; Megeath, S. Thomas; van't Hoff, Merel; Díaz-Rodríguez, Ana Karla; Reynolds, Nickalas; Osorio, Mayra; Anglada, Guillem; Furlan, Elise; Karnath, Nicole; Offner, Stella S. R.; Sheehan, Patrick D.; Sadavoy, Sarah I.; Stutz, Amelia M.; Fischer, William J.; Kama, Mihkel; Persson, Magnus; di Francesco, James; Looney, Leslie W.; Watson, Dan M.; Li, Zhi-Yun; Stephens, Ian; Chandler, Claire J.; Cox, Erin; Dunham, Michael M.; Kratter, Kaitlin; Kounkel, Marina; Mazur, Brian; Murillo, Nadia M.; Patel, Lisa; Perez, Laura; Segura-Cox, Dominique; Sharma, Rajeeb; Tychoniec, Łukasz; Wyrowski, Friedrich
Keywords: SAO
Abstract: We present Atacama Large Millimeter/submillimeter Array (0.87 mm) and Very Large Array (9 mm) observations toward OMC-2 FIR4 and OMC-2 FIR3 within the Orion integral-shaped filament, thought to be two of the nearest regions of intermediate-mass star formation. We characterize the continuum sources within these regions on ∼40 au (0.″1) scales and associated molecular line emission at a factor of ∼30 better resolution than previous observations at similar wavelengths. We identify six compact continuum sources within OMC-2 FIR4, four in OMC-2 FIR3, and one additional source just outside OMC-2 FIR4. This continuum emission is tracing the inner envelope and/or disk emission on less than 100 au scales. HOPS-108 is the only protostar in OMC-2 FIR4 that exhibits emission from high-excitation transitions of complex organic molecules (e.g., methanol and other lines) coincident with the continuum emission. HOPS-370 in OMC-2 FIR3, with L ∼ 360 L , also exhibits emission from high-excitation methanol and other lines. The methanol emission toward these two protostars is indicative of temperatures high enough to thermally evaporate it from icy dust grains; overall, these protostars have characteristics similar to hot corinos. We do not identify a clear outflow from HOPS-108 in 12CO, but we find evidence of interaction between the outflow/jet from HOPS-370 and the OMC-2 FIR4 region. A multitude of observational constraints indicate that HOPS-108 is likely a low- to intermediate-mass protostar in its main mass accretion phase and is the most luminous protostar in OMC-2 FIR4. The high-resolution data presented here are essential for disentangling the embedded protostars from their surrounding dusty environments and characterizing them.
Reply to Li & Yang's comments on 'Comparing the current and early 20th century warm periods in China'Soon, Willie Wei-HockConnolly, RonanConnolly, MichaelO'Neill, PeterZheng, JingyunGe, QuanshengHao, ZhixinYan, Hong2019DOI: info:10.1016/j.earscirev.2019.102950Earth Science Reviewsv. 198 102950 1029500012-8252
Soon, Willie Wei-Hock, Connolly, Ronan, Connolly, Michael, O'Neill, Peter, Zheng, Jingyun, Ge, Quansheng, Hao, Zhixin, and Yan, Hong. 2019. "Reply to Li & Yang's comments on "Comparing the current and early 20th century warm periods in China"." Earth Science Reviews 198: 102950. https://doi.org/10.1016/j.earscirev.2019.102950
ID: 154586
Type: article
Authors: Soon, Willie Wei-Hock; Connolly, Ronan; Connolly, Michael; O'Neill, Peter; Zheng, Jingyun; Ge, Quansheng; Hao, Zhixin; Yan, Hong
Keywords: SAO
Abstract: From a cursory reading of Li & Yang's comments [Li and Yang, 2019, henceforth LY2019] on our recent review article, Soon et al. (2018) [henceforth S2018], some readers might think that LY2019 is somehow disputing our analysis and conclusions. Specifically, they claim to offer "some comments on the arbitrary or deductive conclusions ofSoon et al. (2018)as [sic.] the following five aspects…"
Imaging crystal stress in diamond using ensembles of nitrogen-vacancy centersKehayias, PauliTurner, M. J.Trubko, R.Schloss, J. M.Hart, C. A.Wesson, M.Glenn, D. R.Walsworth, Ronald L.2019DOI: info:10.1103/PhysRevB.100.174103Physical Review Bv. 100 174103 1741031098-0121
Kehayias, Pauli, Turner, M. J., Trubko, R., Schloss, J. M., Hart, C. A., Wesson, M., Glenn, D. R., and Walsworth, Ronald L. 2019. "Imaging crystal stress in diamond using ensembles of nitrogen-vacancy centers." Physical Review B 100: 174103. https://doi.org/10.1103/PhysRevB.100.174103
ID: 154587
Type: article
Authors: Kehayias, Pauli; Turner, M. J.; Trubko, R.; Schloss, J. M.; Hart, C. A.; Wesson, M.; Glenn, D. R.; Walsworth, Ronald L.
Keywords: SAO
Abstract: We present a micrometer-scale-resolution stress imaging method with millimeter field-of-view for diamonds containing a thin surface layer of nitrogen-vacancy (NV) centers. In this method, we reconstruct stress tensor elements over a two-dimensional field of view from NV optically detected magnetic resonance (ODMR) spectra. We use this technique to study how stress inhomogeneity affects NV magnetometry performance and show how NV Mz ,κ imaging is a useful and direct way to assess these effects. This tool for mapping stress in diamond will aid optimization of NV-diamond sensing, with wide-ranging applications in the physical and life sciences.
A BCG with Offset Cooling: Is the AGN Feedback Cycle Broken in A2495?Pasini, T.Gitti, M.Brighenti, F.Temi, P.Amblard, A.Hamer, S. L.Ettori, S.O'Sullivan, EwanGastaldello, F.2019DOI: info:10.3847/1538-4357/ab4808The Astrophysical Journalv. 885 111 1110004-637X
Pasini, T., Gitti, M., Brighenti, F., Temi, P., Amblard, A., Hamer, S. L., Ettori, S., O'Sullivan, Ewan, and Gastaldello, F. 2019. "A BCG with Offset Cooling: Is the AGN Feedback Cycle Broken in A2495?." The Astrophysical Journal 885: 111. https://doi.org/10.3847/1538-4357/ab4808
ID: 154588
Type: article
Authors: Pasini, T.; Gitti, M.; Brighenti, F.; Temi, P.; Amblard, A.; Hamer, S. L.; Ettori, S.; O'Sullivan, Ewan; Gastaldello, F.
Keywords: SAO
Abstract: We present a combined radio/X-ray analysis of the poorly studied galaxy cluster A2495 (z = 0.07923) based on new EVLA and Chandra data. We also analyze and discuss Hα emission and optical continuum data retrieved from the literature. We find an offset of ̃6 kpc between the cluster brightest cluster galaxy (BCG) (MCG+02-58-021) and the peak of the X-ray emission, suggesting that the cooling process is not taking place on the central galaxy nucleus. We propose that sloshing of the intracluster medium (ICM) could be responsible for this separation. Furthermore, we detect a second, ̃4 kpc offset between the peak of the Hα emission and that of the X-ray emission. Optical images highlight the presence of a dust filament extending up to ̃6 kpc in the cluster BCG and allow us to estimate a dust mass within the central 7 kpc of 1.7 × 105 M . Exploiting the dust-to-gas ratio and the L -M mol relation, we argue that a significant amount (up to 109 M ) of molecular gas should be present in the BCG of this cluster. We also investigate the presence of ICM depressions, finding two putative systems of cavities; the inner pair is characterized by t age ̃ 18 Myr and P cav ̃ 1.2 × 1043 erg s-1, the outer one by t age ̃ 53 Myr and P cav ̃ 5.6 × 1042 erg s-1. Their age difference appears to be consistent with the freefall time of the central cooling gas and with the offset timescale estimated with the Hα kinematic data, suggesting that sloshing is likely playing a key role in this environment. Furthermore, the cavities' power analysis shows that the active galactic nucleus energy injection is able to sustain the feedback cycle, despite cooling being offset from the BCG nucleus.
The DECam minute cadence survey - II. 49 variables but no planetary transits of a white dwarfDame, KyraBelardi, ClaudiaKilic, MukreminRest, ArminGianninas, A.Barber, SaraBrown, Warren R.2019DOI: info:10.1093/mnras/stz398Monthly Notices of the Royal Astronomical Societyv. 490 1066 10751066–10750035-8711
Dame, Kyra, Belardi, Claudia, Kilic, Mukremin, Rest, Armin, Gianninas, A., Barber, Sara, and Brown, Warren R. 2019. "The DECam minute cadence survey - II. 49 variables but no planetary transits of a white dwarf." Monthly Notices of the Royal Astronomical Society 490: 1066– 1075. https://doi.org/10.1093/mnras/stz398
ID: 154589
Type: article
Authors: Dame, Kyra; Belardi, Claudia; Kilic, Mukremin; Rest, Armin; Gianninas, A.; Barber, Sara; Brown, Warren R.
Keywords: SAO
Abstract: We present minute cadence photometry of 31 732 point sources observed in one 3 deg2 DECam pointing centred at RA = 09:03:02 and Dec. = -04:35:00 over eight consecutive half-nights. We use these data to search for eclipse-like events consistent with a planetary transit of a white dwarf and other sources of stellar variability within the field. We do not find any significant evidence for minute-long transits around our targets, hence we rule out planetary transits around ̃370 white dwarfs that should be present in this field. Additionally, we identify 49 variables, including 40 new systems. These include 23 detached or contact stellar binaries, one eclipsing white dwarf + M dwarf binary, 16 δ Scuti, three RR Lyrae, and two ZZ Ceti pulsators. Results from the remaining two fields in our survey will allow us to place more stringent constraints on the frequency of planets orbiting white dwarfs in the habitable zone.
A comprehensive three-dimensional radiative magnetohydrodynamic simulation of a solar flareCheung, M. C. M.Rempel, M.Chintzoglou, G.Chen, F.Testa, PaolaMartínez-Sykora, J.Sainz Dalda, A.DeRosa, M. L.Malanushenko, A.Hansteen, V.De Pontieu, B.Carlsson, M.Gudiksen, B.McIntosh, S. W.2019DOI: info:10.1038/s41550-018-0629-3Nature Astronomyv. 3 160 166160–1662397-3366
Cheung, M. C. M., Rempel, M., Chintzoglou, G., Chen, F., Testa, Paola, Martínez-Sykora, J., Sainz Dalda, A., DeRosa, M. L., Malanushenko, A., Hansteen, V., De Pontieu, B., Carlsson, M., Gudiksen, B., and McIntosh, S. W. 2019. "A comprehensive three-dimensional radiative magnetohydrodynamic simulation of a solar flare." Nature Astronomy 3: 160– 166. https://doi.org/10.1038/s41550-018-0629-3
ID: 154590
Type: article
Authors: Cheung, M. C. M.; Rempel, M.; Chintzoglou, G.; Chen, F.; Testa, Paola; Martínez-Sykora, J.; Sainz Dalda, A.; DeRosa, M. L.; Malanushenko, A.; Hansteen, V.; De Pontieu, B.; Carlsson, M.; Gudiksen, B.; McIntosh, S. W.
Keywords: SAO
Abstract: Solar and stellar flares are the most intense emitters of X-rays and extreme ultraviolet radiation in planetary systems1,2. On the Sun, strong flares are usually found in newly emerging sunspot regions3. The emergence of these magnetic sunspot groups leads to the accumulation of magnetic energy in the corona. When the magnetic field undergoes abrupt relaxation, the energy released powers coronal mass ejections as well as heating plasma to temperatures beyond tens of millions of kelvins. While recent work has shed light on how magnetic energy and twist accumulate in the corona4 and on how three-dimensional magnetic reconnection allows for rapid energy release5,6, a self-consistent model capturing how such magnetic changes translate into observable diagnostics has remained elusive. Here, we present a comprehensive radiative magnetohydrodynamics simulation of a solar flare capturing the process from emergence to eruption. The simulation has sufficient realism for the synthesis of remote sensing measurements to compare with observations at visible, ultraviolet and X-ray wavelengths. This unifying model allows us to explain a number of well-known features of solar flares7, including the time profile of the X-ray flux during flares, origin and temporal evolution of chromospheric evaporation and condensation, and sweeping of flare ribbons in the lower atmosphere. Furthermore, the model reproduces the apparent non-thermal shape of coronal X-ray spectra, which is the result of the superposition of multi-component super-hot plasmas8 up to and beyond 100 million K.
Near-resonance in a System of Sub-Neptunes from TESSQuinn, Samuel N.Becker, Juliette C.Rodriguez, Joseph E.Hadden, SamHuang, Chelsea X.Morton, Timothy D.Adams, Fred C.Armstrong, DavidEastman, Jason D.Horner, JonathanKane, Stephen R.Lissauer, Jack J.Twicken, Joseph D.Vanderburg, AndrewWittenmyer, RobRicker, George R.Vanderspek, Roland K.Latham, David W.Seager, SaraWinn, Joshua N.Jenkins, Jon M.Agol, EricBarkaoui, KhalidBeichman, Charles A.Bouchy, FrançoisBouma, L. G.Burdanov, ArtemCampbell, JenniferCarlino, RobertoCartwright, Scott M.Charbonneau, DavidChristiansen, Jessie L.Ciardi, DavidCollins, Karen A.Collins, Kevin I.Conti, Dennis M.Crossfield, Ian J. M.Daylan, TansuDittmann, JasonDoty, JohnDragomir, DianaDucrot, ElsaGillon, MichaelGlidden, AnaGoeke, Robert F.Gonzales, Erica J.Hełminiak, Krzysztof G.Horch, Elliott P.Howell, Steve B.Jehin, EmmanuelJensen, Eric L. N.Kielkopf, John F.Kristiansen, Martti H.Law, NicholasMann, Andrew W.Marmier, MaximeMatson, Rachel A.Matthews, ElisabethMazeh, TseviMori, MayukoMurgas, FelipeMurray, CatrionaNarita, NorioNielsen, Louise D.Ottoni, GaëlPalle, EnricPawłaszek, RafałPepe, FrancescoPitogo de Leon, JeromePozuelos, Francisco J.Relles, Howard M.Schlieder, Joshua E.Sebastian, DanielSégransan, DamienShporer, AviStassun, Keivan G.Tamura, MotohideUdry, StéphaneWaite, IanWinters, Jennifer G.Ziegler, Carl2019DOI: info:10.3847/1538-3881/ab3f2bThe Astronomical Journalv. 158 177 1770004-6256
Quinn, Samuel N., Becker, Juliette C., Rodriguez, Joseph E., Hadden, Sam, Huang, Chelsea X., Morton, Timothy D., Adams, Fred C., Armstrong, David, Eastman, Jason D., Horner, Jonathan, Kane, Stephen R., Lissauer, Jack J., Twicken, Joseph D., Vanderburg, Andrew, Wittenmyer, Rob, Ricker, George R., Vanderspek, Roland K., Latham, David W., Seager, Sara, Winn, Joshua N., Jenkins, Jon M., Agol, Eric, Barkaoui, Khalid, Beichman, Charles A., Bouchy, François et al. 2019. "Near-resonance in a System of Sub-Neptunes from TESS." The Astronomical Journal 158: 177. https://doi.org/10.3847/1538-3881/ab3f2b
ID: 154591
Type: article
Authors: Quinn, Samuel N.; Becker, Juliette C.; Rodriguez, Joseph E.; Hadden, Sam; Huang, Chelsea X.; Morton, Timothy D.; Adams, Fred C.; Armstrong, David; Eastman, Jason D.; Horner, Jonathan; Kane, Stephen R.; Lissauer, Jack J.; Twicken, Joseph D.; Vanderburg, Andrew; Wittenmyer, Rob; Ricker, George R.; Vanderspek, Roland K.; Latham, David W.; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Agol, Eric; Barkaoui, Khalid; Beichman, Charles A.; Bouchy, François; Bouma, L. G.; Burdanov, Artem; Campbell, Jennifer; Carlino, Roberto; Cartwright, Scott M.; Charbonneau, David; Christiansen, Jessie L.; Ciardi, David; Collins, Karen A.; Collins, Kevin I.; Conti, Dennis M.; Crossfield, Ian J. M.; Daylan, Tansu; Dittmann, Jason; Doty, John; Dragomir, Diana; Ducrot, Elsa; Gillon, Michael; Glidden, Ana; Goeke, Robert F.; Gonzales, Erica J.; Hełminiak, Krzysztof G.; Horch, Elliott P.; Howell, Steve B.; Jehin, Emmanuel; Jensen, Eric L. N.; Kielkopf, John F.; Kristiansen, Martti H.; Law, Nicholas; Mann, Andrew W.; Marmier, Maxime; Matson, Rachel A.; Matthews, Elisabeth; Mazeh, Tsevi; Mori, Mayuko; Murgas, Felipe; Murray, Catriona; Narita, Norio; Nielsen, Louise D.; Ottoni, Gaël; Palle, Enric; Pawłaszek, Rafał; Pepe, Francesco; Pitogo de Leon, Jerome; Pozuelos, Francisco J.; Relles, Howard M.; Schlieder, Joshua E.; Sebastian, Daniel; Ségransan, Damien; Shporer, Avi; Stassun, Keivan G.; Tamura, Motohide; Udry, Stéphane; Waite, Ian; Winters, Jennifer G.; Ziegler, Carl
Keywords: SAO
Abstract: We report the Transiting Exoplanet Survey Satellite detection of a multi-planet system orbiting the V = 10.9 K0 dwarf TOI-125. We find evidence for up to five planets, with varying confidence. Three transit signals with high signal-to-noise ratio correspond to sub-Neptune-sized planets (2.76, 2.79, and 2.94 R ), and we statistically validate the planetary nature of the two inner planets (P b = 4.65 days, P c = 9.15 days). With only two transits observed, we report the outer object (P .03 = 19.98 days) as a planet candidate with high signal-to-noise ratio. We also detect a candidate transiting super-Earth (1.4 R ) with an orbital period of only 12.7 hr and a candidate Neptune-sized planet (4.2 R ) with a period of 13.28 days, both at low signal-to-noise ratio. This system is amenable to mass determination via radial velocities and transit-timing variations, and provides an opportunity to study planets of similar size while controlling for age and environment. The ratio of orbital periods between TOI-125 b and c (P c /P b = 1.97) is slightly lower than an exact 2:1 commensurability and is atypical of multiple planet systems from Kepler, which show a preference for period ratios just wide of first-order period ratios. A dynamical analysis refines the allowed parameter space through stability arguments and suggests that despite the nearly commensurate periods, the system is unlikely to be in resonance.
TOI-150b and TOI-163b: two transiting hot Jupiters, one eccentric and one inflated, revealed by TESS near and at the edge of the JWST CVZKossakowski, DianaEspinoza, NéstorBrahm, RafaelJordán, AndrésHenning, ThomasRojas, FelipeKürster, MartinSarkis, PaulaSchlecker, MartinPozuelos, Francisco J.Barkaoui, KhalidJehin, EmmanuëlGillon, MichaëlMatthews, ElisabethHorch, Elliott P.Ciardi, David R.Crossfield, Ian J. M.Gonzales, EricaHowell, Steve B.Matson, RachelSchlieder, JoshuaJenkins, JonRicker, GeorgeSeager, SaraWinn, Joshua N.Li, JieRose, Mark E.Smith, Jeffrey C.Dynes, ScottMorgan, EdVillasenor, Jesus NoelCharbonneau, DavidJaffe, TessYu, LiangBakos, GasparBhatti, WaqasBouchy, FrançoisCollins, Karen A.Collins, Kevin I.Csubry, ZoltanEvans, PhilJensen, Eric L. N.Lovis, ChristopheMarmier, MaximeNielsen, Louise D.Osip, DavidPepe, FrancescoRelles, Howard M.Ségransan, DamienShporer, AviStockdale, ChrisSuc, VincentTurner, OliverUdry, Stéphane2019DOI: info:10.1093/mnras/stz2433Monthly Notices of the Royal Astronomical Societyv. 490 1094 11101094–11100035-8711
Kossakowski, Diana, Espinoza, Néstor, Brahm, Rafael, Jordán, Andrés, Henning, Thomas, Rojas, Felipe, Kürster, Martin, Sarkis, Paula, Schlecker, Martin, Pozuelos, Francisco J., Barkaoui, Khalid, Jehin, Emmanuël, Gillon, Michaël, Matthews, Elisabeth, Horch, Elliott P., Ciardi, David R., Crossfield, Ian J. M., Gonzales, Erica, Howell, Steve B., Matson, Rachel, Schlieder, Joshua, Jenkins, Jon, Ricker, George, Seager, Sara, Winn, Joshua N. et al. 2019. "TOI-150b and TOI-163b: two transiting hot Jupiters, one eccentric and one inflated, revealed by TESS near and at the edge of the JWST CVZ." Monthly Notices of the Royal Astronomical Society 490: 1094– 1110. https://doi.org/10.1093/mnras/stz2433
ID: 154592
Type: article
Authors: Kossakowski, Diana; Espinoza, Néstor; Brahm, Rafael; Jordán, Andrés; Henning, Thomas; Rojas, Felipe; Kürster, Martin; Sarkis, Paula; Schlecker, Martin; Pozuelos, Francisco J.; Barkaoui, Khalid; Jehin, Emmanuël; Gillon, Michaël; Matthews, Elisabeth; Horch, Elliott P.; Ciardi, David R.; Crossfield, Ian J. M.; Gonzales, Erica; Howell, Steve B.; Matson, Rachel; Schlieder, Joshua; Jenkins, Jon; Ricker, George; Seager, Sara; Winn, Joshua N.; Li, Jie; Rose, Mark E.; Smith, Jeffrey C.; Dynes, Scott; Morgan, Ed; Villasenor, Jesus Noel; Charbonneau, David; Jaffe, Tess; Yu, Liang; Bakos, Gaspar; Bhatti, Waqas; Bouchy, François; Collins, Karen A.; Collins, Kevin I.; Csubry, Zoltan; Evans, Phil; Jensen, Eric L. N.; Lovis, Christophe; Marmier, Maxime; Nielsen, Louise D.; Osip, David; Pepe, Francesco; Relles, Howard M.; Ségransan, Damien; Shporer, Avi; Stockdale, Chris; Suc, Vincent; Turner, Oliver; Udry, Stéphane
Keywords: SAO
Abstract: We present the discovery of TYC9191-519-1b (TOI-150b, TIC 271893367) and HD271181b (TOI-163b, TIC 179317684), two hot Jupiters initially detected using 30-min cadence Transiting Exoplanet Survey Satellite (TESS) photometry from Sector 1 and thoroughly characterized through follow-up photometry (CHAT, Hazelwood, LCO/CTIO, El Sauce, TRAPPIST-S), high- resolution spectroscopy (FEROS, CORALIE), and speckle imaging (Gemini/DSSI), confirming the planetary nature of the two signals. A simultaneous joint fit of photometry and radial velocity using a new fitting package JULIET reveals that TOI-150b is a 1.254± 0.016 {R}_ {J}, massive (2.61^{+0.19}_{-0.12} {M}_ {J}) hot Jupiter in a 5.857-d orbit, while TOI-163b is an inflated (R_ {P} = 1.478^{+0.022}_{-0.029} R_ {J}, M_ {P} = 1.219± 0.11 {M}_ {J}) hot Jupiter on a P = 4.231-d orbit; both planets orbit F-type stars. A particularly interesting result is that TOI-150b shows an eccentric orbit (e=0.262^{+0.045}_{-0.037}), which is quite uncommon among hot Jupiters. We estimate that this is consistent, however, with the circularization time-scale, which is slightly larger than the age of the system. These two hot Jupiters are both prime candidates for further characterization - in particular, both are excellent candidates for determining spin-orbit alignments via the Rossiter-McLaughlin (RM) effect and for characterizing atmospheric thermal structures using secondary eclipse observations considering they are both located closely to the James Webb Space Telescope (JWST) Continuous Viewing Zone (CVZ).
A noninteracting low-mass black hole─giant star binary systemThompson, Todd A.Kochanek, Christopher S.Stanek, Krzysztof Z.Badenes, CarlesPost, Richard S.Jayasinghe, TharinduLatham, David W.Bieryla, AllysonEsquerdo, Gilbert A.Berlind, PerryCalkins, Michael L.Tayar, JamieLindegren, LennartJohnson, Jennifer A.Holoien, Thomas W. -SAuchettl, KatieCovey, Kevin2019DOI: info:10.1126/science.aau4005Sciencev. 366 637 640637–6400036-8075
Thompson, Todd A., Kochanek, Christopher S., Stanek, Krzysztof Z., Badenes, Carles, Post, Richard S., Jayasinghe, Tharindu, Latham, David W., Bieryla, Allyson, Esquerdo, Gilbert A., Berlind, Perry, Calkins, Michael L., Tayar, Jamie, Lindegren, Lennart, Johnson, Jennifer A., Holoien, Thomas W. -S, Auchettl, Katie, and Covey, Kevin. 2019. "A noninteracting low-mass black hole─giant star binary system." Science 366: 637– 640. https://doi.org/10.1126/science.aau4005
ID: 154593
Type: article
Authors: Thompson, Todd A.; Kochanek, Christopher S.; Stanek, Krzysztof Z.; Badenes, Carles; Post, Richard S.; Jayasinghe, Tharindu; Latham, David W.; Bieryla, Allyson; Esquerdo, Gilbert A.; Berlind, Perry; Calkins, Michael L.; Tayar, Jamie; Lindegren, Lennart; Johnson, Jennifer A.; Holoien, Thomas W. -S; Auchettl, Katie; Covey, Kevin
Keywords: SAO
Abstract: Black hole binary systems with companion stars are typically found via their x-ray emission, generated by interaction and accretion. Noninteracting binaries are expected to be plentiful in the Galaxy but must be observed using other methods. We combine radial velocity and photometric variability data to show that the bright, rapidly rotating giant star 2MASS J05215658+4359220 is in a binary system with a massive unseen companion. The system has an orbital period of ~83 days and near- zero eccentricity. The photometric variability period of the giant is consistent with the orbital period, indicating star spots and tidal synchronization. Constraints on the giant's mass and radius imply that the unseen companion is 3.3−0.7+2.8 solar masses, indicating that it is a noninteracting low-mass black hole or an unexpectedly massive neutron star.
The γ-ray sky seen at X-ray energies. I. Searching for the connection between X-rays and γ-rays in Fermi BL Lac objectsMarchesini, E. J.Paggi, A.Massaro, F.Masetti, N.D'Abrusco, RaffaeleAndruchow, I.de Menezes, R.2019DOI: info:10.1051/0004-6361/201936285Astronomy and Astrophysicsv. 631 A150 A1500004-6361
Marchesini, E. J., Paggi, A., Massaro, F., Masetti, N., D'Abrusco, Raffaele, Andruchow, I., and de Menezes, R. 2019. "The γ-ray sky seen at X-ray energies. I. Searching for the connection between X-rays and γ-rays in Fermi BL Lac objects." Astronomy and Astrophysics 631: A150. https://doi.org/10.1051/0004-6361/201936285
ID: 154594
Type: article
Authors: Marchesini, E. J.; Paggi, A.; Massaro, F.; Masetti, N.; D'Abrusco, Raffaele; Andruchow, I.; de Menezes, R.
Keywords: SAO
Abstract: Context. BL Lac objects are an extreme type of active galactic nuclei (AGNs) that belong to the largest population of γ-ray sources: blazars. This class of AGNs shows a double-bumped spectral energy distribution that is commonly described in terms of a synchrotron self-Compton (SSC) emission process, whereas the low-energy component that dominates their emission between the infrared and the X-ray band is tightly connected to the high-energy component that peaks in the γ-rays. Two strong connections that link radio and mid-infrared emission of blazars to the emission in the γ-ray band are well established. They constitute the basis for associating γ-ray sources with their low-energy counterparts. Aims: We searched for a possible link between X-ray and γ-ray emissions for the subclass of BL Lacs using all archival Swift/XRT observations combined with Fermi data for a selected sample of 351 sources. Methods: Analyzing ̃2400 ks of Swift/XRT observations that were carried out until December 2018, we discovered that above the γ-ray flux threshold Fγ ≈ 3 × 10-12 erg cm-2 s-1, 96% of all Fermi BL Lacs have an X-ray counterpart that is detected with signal-to-noise ratio > 3. Results: We did not find any correlation or clear trend between X-ray and γ-ray fluxes and/or spectral shapes, but we discovered a correlation between the X-ray flux and the mid-infrared color. Finally, we discuss on a possible interpretation of our results in the SSC framework. Full Table 1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz- bin/cat/J/A+A/631/A150
KELT-24b: A 5M J Planet on a 5.6 day Well-aligned Orbit around the Young V = 8.3 F-star HD 93148Rodriguez, Joseph E.Eastman, Jason D.Zhou, GeorgeQuinn, Samuel N.Beatty, Thomas G.Penev, KaloyanJohnson, Marshall C.Cargile, Phillip A.Latham, David W.Bieryla, AllysonCollins, Karen A.Dressing, Courtney D.Ciardi, David R.Relles, Howard M.Murawski, GabrielNishiumi, TakuYonehara, AtsunoriIshimaru, RyoYoshida, FumiGregorio, JoaoLund, Michael B.Stevens, Daniel J.Stassun, Keivan G.Gaudi, B. ScottColón, Knicole D.Pepper, JoshuaNarita, NorioAwiphan, SupachaiChuanraksasat, PongpichitBenni, PaulZambelli, RobertoGarrison, Lehman H.Wilson, Maurice L.Cornachione, Matthew A.Wang, Sharon X.Labadie-Bartz, JonathanRodríguez, RomySiverd, Robert J.Yao, XinyuBayliss, DanielBerlind, PerryCalkins, Michael L.Christiansen, Jessie L.Cohen, David H.Conti, Dennis M.Curtis, Ivan A.DePoy, D. L.Esquerdo, Gilbert A.Evans, PhilFeliz, DaxFulton, Benjamin J.Holoien, Thomas W. -SJames, David J.Jayasinghe, TharinduJang-Condell, HannahJensen, Eric L. N.Johnson, John A.Joner, Michael D.Khakpash, SomayehKielkopf, John F.Kuhn, Rudolf B.Manner, MarkMarshall, Jennifer L.McLeod, Kim K.McCrady, NateOberst, Thomas E.Oelkers, Ryan J.Penny, Matthew T.Reed, Phillip A.Sliski, David H.Shappee, B. J.Stephens, Denise C.Stockdale, ChrisTan, Thiam-GuanTrueblood, MarkTrueblood, PatVillanueva, Steven, Jr.Wittenmyer, Robert A.Wright, Jason T.2019DOI: info:10.3847/1538-3881/ab4136The Astronomical Journalv. 158 197 1970004-6256
Rodriguez, Joseph E., Eastman, Jason D., Zhou, George, Quinn, Samuel N., Beatty, Thomas G., Penev, Kaloyan, Johnson, Marshall C., Cargile, Phillip A., Latham, David W., Bieryla, Allyson, Collins, Karen A., Dressing, Courtney D., Ciardi, David R., Relles, Howard M., Murawski, Gabriel, Nishiumi, Taku, Yonehara, Atsunori, Ishimaru, Ryo, Yoshida, Fumi, Gregorio, Joao, Lund, Michael B., Stevens, Daniel J., Stassun, Keivan G., Gaudi, B. Scott, Colón, Knicole D. et al. 2019. "KELT-24b: A 5M J Planet on a 5.6 day Well-aligned Orbit around the Young V = 8.3 F-star HD 93148." The Astronomical Journal 158: 197. https://doi.org/10.3847/1538-3881/ab4136
ID: 154595
Type: article
Authors: Rodriguez, Joseph E.; Eastman, Jason D.; Zhou, George; Quinn, Samuel N.; Beatty, Thomas G.; Penev, Kaloyan; Johnson, Marshall C.; Cargile, Phillip A.; Latham, David W.; Bieryla, Allyson; Collins, Karen A.; Dressing, Courtney D.; Ciardi, David R.; Relles, Howard M.; Murawski, Gabriel; Nishiumi, Taku; Yonehara, Atsunori; Ishimaru, Ryo; Yoshida, Fumi; Gregorio, Joao; Lund, Michael B.; Stevens, Daniel J.; Stassun, Keivan G.; Gaudi, B. Scott; Colón, Knicole D.; Pepper, Joshua; Narita, Norio; Awiphan, Supachai; Chuanraksasat, Pongpichit; Benni, Paul; Zambelli, Roberto; Garrison, Lehman H.; Wilson, Maurice L.; Cornachione, Matthew A.; Wang, Sharon X.; Labadie-Bartz, Jonathan; Rodríguez, Romy; Siverd, Robert J.; Yao, Xinyu; Bayliss, Daniel; Berlind, Perry; Calkins, Michael L.; Christiansen, Jessie L.; Cohen, David H.; Conti, Dennis M.; Curtis, Ivan A.; DePoy, D. L.; Esquerdo, Gilbert A.; Evans, Phil; Feliz, Dax; Fulton, Benjamin J.; Holoien, Thomas W. -S; James, David J.; Jayasinghe, Tharindu; Jang-Condell, Hannah; Jensen, Eric L. N.; Johnson, John A.; Joner, Michael D.; Khakpash, Somayeh; Kielkopf, John F.; Kuhn, Rudolf B.; Manner, Mark; Marshall, Jennifer L.; McLeod, Kim K.; McCrady, Nate; Oberst, Thomas E.; Oelkers, Ryan J.; Penny, Matthew T.; Reed, Phillip A.; Sliski, David H.; Shappee, B. J.; Stephens, Denise C.; Stockdale, Chris; Tan, Thiam-Guan; Trueblood, Mark; Trueblood, Pat; Villanueva, Steven, Jr.; Wittenmyer, Robert A.; Wright, Jason T.
Keywords: SAO
Abstract: We present the discovery of KELT-24 b, a massive hot Jupiter orbiting a bright (V = 8.3 mag, K = 7.2 mag) young F-star with a period of 5.6 days. The host star, KELT-24 (HD 93148), has a T eff = {6509}-49+50 K, a mass of M * = {1.460}-0.059+0.055 M , a radius of R * = 1.506 ± 0.022 R , and an age of {0.78}-0.42+0.61 Gyr. Its planetary companion (KELT-24 b) has a radius of R P = 1.272 ± 0.021 R J and a mass of M P = {5.18}-0.22+0.21 M J, and from Doppler tomographic observations, we find that the planet's orbit is well- aligned to its host star's projected spin axis (λ ={2.6}-3.6+5.1). The young age estimated for KELT-24 suggests that it only recently started to evolve from the zero- age main sequence. KELT-24 is the brightest star known to host a transiting giant planet with a period between 5 and 10 days. Although the circularization timescale is much longer than the age of the system, we do not detect a large eccentricity or significant misalignment that is expected from dynamical migration. The brightness of its host star and its moderate surface gravity make KELT-24b an intriguing target for detailed atmospheric characterization through spectroscopic emission measurements since it would bridge the current literature results that have primarily focused on lower mass hot Jupiters and a few brown dwarfs.
Dust Polarization toward Embedded Protostars in Ophiuchus with ALMA. III. Survey OverviewSadavoy, Sarah I.Stephens, Ian W.Myers, Philip C.Looney, LeslieTobin, JohnKwon, WoojinCommerçon, BenoîtSegura-Cox, DominiqueHenning, ThomasHennebelle, Patrick2019DOI: info:10.3847/1538-4365/ab4257The Astrophysical Journal Supplement Seriesv. 245 2 20067-0049
Sadavoy, Sarah I., Stephens, Ian W., Myers, Philip C., Looney, Leslie, Tobin, John, Kwon, Woojin, Commerçon, Benoît, Segura-Cox, Dominique, Henning, Thomas, and Hennebelle, Patrick. 2019. "Dust Polarization toward Embedded Protostars in Ophiuchus with ALMA. III. Survey Overview." The Astrophysical Journal Supplement Series 245: 2. https://doi.org/10.3847/1538-4365/ab4257
ID: 154596
Type: article
Authors: Sadavoy, Sarah I.; Stephens, Ian W.; Myers, Philip C.; Looney, Leslie; Tobin, John; Kwon, Woojin; Commerçon, Benoît; Segura-Cox, Dominique; Henning, Thomas; Hennebelle, Patrick
Keywords: SAO
Abstract: We present 0.″25 resolution (35 au) ALMA 1.3 mm dust polarization observations for 37 young stellar objects (YSOs) in the Ophiuchus molecular cloud. These data encompass all the embedded protostars in the cloud and several flat-spectrum and Class II objects to produce the largest, homogeneous study of dust polarization on disk scales to date. The goal of this study is to study dust polarization morphologies down to disk scales. We find that 14/37 (38%) of the observed YSOs are detected in polarization at our sensitivity. Nine of these sources have uniform polarization angles, and four sources have azimuthal polarization structure. We find that the sources with uniform polarization tend to have steeper inclinations (>60°) than those with azimuthal polarization (60° are the best candidates for future polarization studies of dust self-scattering, as these systems will generally show uniform polarization vectors that do not require very high resolution to resolve. We release the continuum and polarization images for all the sources with this publication. Data from the entire survey can be obtained from Dataverse.
Imaging [CI] around HD 131835: reinterpreting young debris discs with protoplanetary disc levels of CO gas as shielded secondary discsKral, QuentinMarino, SebastianWyatt, Mark C.Kama, MihkelMatrà, Luca2019DOI: info:10.1093/mnras/sty2923Monthly Notices of the Royal Astronomical Societyv. 489 3670 36913670–36910035-8711
Kral, Quentin, Marino, Sebastian, Wyatt, Mark C., Kama, Mihkel, and Matrà, Luca. 2019. "Imaging [CI] around HD 131835: reinterpreting young debris discs with protoplanetary disc levels of CO gas as shielded secondary discs." Monthly Notices of the Royal Astronomical Society 489: 3670– 3691. https://doi.org/10.1093/mnras/sty2923
ID: 154597
Type: article
Authors: Kral, Quentin; Marino, Sebastian; Wyatt, Mark C.; Kama, Mihkel; Matrà, Luca
Keywords: SAO
Abstract: Despite being >10 Myr, there are ∼10 debris discs with as much CO gas as in protoplanetary discs. Such discs have been assumed to be 'hybrid', i.e. with secondary dust but primordial gas. Here, we show that both the dust and gas in such systems could instead be secondary, with the high CO content caused by accumulation of neutral carbon (C0) that shields CO from photodissociating; i.e. these could be 'shielded secondary discs'. New ALMA observations are presented of HD131835 that detect ∼3 × 10-3 M of C0, the majority 40-200 au from the star, in sufficient quantity to shield the previously detected CO. A simple semi-analytic model for the evolution of CO, C, and O originating in a volatile-rich planetesimal belt shows how CO shielding becomes important when the viscous evolution is slow (low α parameter) and/or the CO production rate is high. Shielding by C0 may also cause the CO content to reach levels at which CO self-shields, and the gas disc may become massive enough to affect the dust evolution. Application to the HD 131835 observations shows these can be explained if α ∼ 10-3; an inner cavity in C0 and CO may also mean the system has yet to reach steady state. Application to other debris discs with high CO content finds general agreement for α = 10-3 to 0.1. The shielded secondary nature of these gas discs can be tested by searching for C0, as well as CN, N2, and CH+, which are also expected to be shielded by C0.
UGC 1378 - a Milky Way sized galaxy embedded in a giant low surface brightness discSaburova, Anna S.Chilingarian, Igor V.Kasparova, Anastasia V.Katkov, Ivan YuFabricant, Daniel G.Uklein, Roman I.2019DOI: info:10.1093/mnras/stz2434Monthly Notices of the Royal Astronomical Societyv. 489 4669 46784669–46780035-8711
Saburova, Anna S., Chilingarian, Igor V., Kasparova, Anastasia V., Katkov, Ivan Yu, Fabricant, Daniel G., and Uklein, Roman I. 2019. "UGC 1378 - a Milky Way sized galaxy embedded in a giant low surface brightness disc." Monthly Notices of the Royal Astronomical Society 489: 4669– 4678. https://doi.org/10.1093/mnras/stz2434
ID: 154598
Type: article
Authors: Saburova, Anna S.; Chilingarian, Igor V.; Kasparova, Anastasia V.; Katkov, Ivan Yu; Fabricant, Daniel G.; Uklein, Roman I.
Keywords: SAO
Abstract: The dominant physical processes responsible for the formation and longevity of giant gaseous and stellar discs in galaxies remain controversial. Although they are rare (less than 10 confirmed as of now), giant low-surface brightness (gLSB) discy galaxies provide interesting insights given their extreme nature. We describe observations of UGC 1378 including deep spectroscopy with the Russian 6-m telescope and multiband imaging with Binospec at the MMT. Galaxy UGC 1378 has both high surface brightness and an extended low surface brightness discs. Our stellar velocity dispersion data for the high surface brightness, Milky Way sized, disc appears inconsistent with a recent major merger, a widely discussed formation scenario for the very extended low surface brightness disc. We estimate the star formation rates (SFRs) from archival Wide-Field Infrared Survey Explorer data. The SFR surface density in the LSB disc is low relative to its gas density, consistent with recent gas accretion. We argue that the unusually large size of UGC 1378's disc may be the product of a rich gas reservoir (e.g. a cosmic filament) and an isolated environment that has preserved the giant disc.
Discrete star formation events in the central bar of the Small Magellanic CloudStrantzalis, A.Hatzidimitriou, D.Zezas, A.Antoniou, ValliaLianou, S.Tsilia, S.2019DOI: info:10.1093/mnras/stz2540Monthly Notices of the Royal Astronomical Societyv. 489 5087 50975087–50970035-8711
Strantzalis, A., Hatzidimitriou, D., Zezas, A., Antoniou, Vallia, Lianou, S., and Tsilia, S. 2019. "Discrete star formation events in the central bar of the Small Magellanic Cloud." Monthly Notices of the Royal Astronomical Society 489: 5087– 5097. https://doi.org/10.1093/mnras/stz2540
ID: 154599
Type: article
Authors: Strantzalis, A.; Hatzidimitriou, D.; Zezas, A.; Antoniou, Vallia; Lianou, S.; Tsilia, S.
Keywords: SAO
Abstract: We present the results of the photometric analysis of a large part of the main body of the Small Magellanic Cloud. Using the 6.5m Magellan Telescope at the Las Campanas Observatory in Chile, we have acquired deep B and I images in four fields (0.44 deg each in diameter), yielding accurate photometry for 1068 893 stars down to 24th magnitude, with a spatial resolution of 0.20 arcsec per pixel. Colour-magnitude diagrams and (completeness-corrected) luminosity functions have been constructed, yielding significant new results that indicate at least two discrete star formation events over a period from 2.7 to 4 Gyr ago. Also, we have derived star formation rates as a function of look-back time and have found enhancements of SF between 4 and 6 Gyr and at younger ages.
ALMA Observations of Fragmentation, Substructure, and Protostars in High-mass Starless Clump CandidatesSvoboda, Brian E.Shirley, Yancy L.Traficante, AlessioBattersby, CaraFuller, Gary A.Zhang, QizhouBeuther, HenrikPeretto, NicolasBrogan, CrystalHunter, Todd2019DOI: info:10.3847/1538-4357/ab40caThe Astrophysical Journalv. 886 36 360004-637X
Svoboda, Brian E., Shirley, Yancy L., Traficante, Alessio, Battersby, Cara, Fuller, Gary A., Zhang, Qizhou, Beuther, Henrik, Peretto, Nicolas, Brogan, Crystal, and Hunter, Todd. 2019. "ALMA Observations of Fragmentation, Substructure, and Protostars in High-mass Starless Clump Candidates." The Astrophysical Journal 886: 36. https://doi.org/10.3847/1538-4357/ab40ca
ID: 154600
Type: article
Authors: Svoboda, Brian E.; Shirley, Yancy L.; Traficante, Alessio; Battersby, Cara; Fuller, Gary A.; Zhang, Qizhou; Beuther, Henrik; Peretto, Nicolas; Brogan, Crystal; Hunter, Todd
Keywords: SAO
Abstract: The initial physical conditions of high-mass stars and protoclusters remain poorly characterized. To this end, we present the first targeted ALMA Band 6 1.3 mm continuum and spectral line survey toward high-mass starless clump candidates, selecting a sample of 12 of the most massive candidates (4× {10}2 {M}ȯ ≲ {M}cl}≲ 4× {10}3 {M}ȯ ) within {d}ȯ syn ≈ 0.″8) and have high point-source mass-completeness down to M≈ 0.3 {M}ȯ at 6{σ }rms} (or 1{σ }rms} column density sensitivity of N=1.1× {10}22 {cm}}-2). We discover previously undetected signposts of low-luminosity star formation from {CO} J=2\to 1 and {SiO} J=5\to 4 bipolar outflows and other signatures toward 11 out of 12 clumps, showing that current MIR/FIR Galactic plane surveys are incomplete to low- and intermediate-mass protostars ({L}bol}≲ 50 {L}ȯ ), and emphasizing the necessity of high-resolution follow-up. We compare a subset of the observed cores with a suite of radiative transfer models of starless cores. We find a high-mass starless core candidate with a model-derived mass consistent with {29}1552 {M}ȯ when integrated over size scales of R when integrated over size scales of R4 {au}. Unresolved cores are poorly fit by radiative transfer models of externally heated Plummer density profiles, supporting the interpretation that they are protostellar even without detection of outflows. A high degree of fragmentation with rich substructure is observed toward 10 out of 12 clumps. We extract sources from the maps using a dendrogram to study the characteristic fragmentation length scale. Nearest neighbor separations, when corrected for projection with Monte Carlo random sampling, are consistent with being equal to the clump average thermal Jeans length ({λ }{{j},{th}}; i.e., separations equal to 0.4{--}1.6× {λ }{{j},{th}}). In the context of previous observations that, on larger scales, see separations consistent with the turbulent Jeans length or the cylindrical thermal Jeans scale (≈ 3{--}4× {λ }{{j},{th}}), our findings support a hierarchical fragmentation process, where the highest-density regions are not strongly supported against thermal gravitational fragmentation by turbulence or magnetic fields.
The MOSDEF Survey: The Metallicity Dependence of X-Ray Binary Populations at z ̃ 2Fornasini, Francesca M.Kriek, MariskaSanders, Ryan L.Shivaei, IreneCivano, FrancescaReddy, Naveen A.Shapley, Alice E.Coil, Alison L.Mobasher, BahramSiana, BrianAird, JamesAzadi, MojeganFreeman, William R.Leung, Gene C. K.Price, Sedona H.Fetherolf, TaraZick, TomBarro, Guillermo2019DOI: info:10.3847/1538-4357/ab4653The Astrophysical Journalv. 885 65 650004-637X
Fornasini, Francesca M., Kriek, Mariska, Sanders, Ryan L., Shivaei, Irene, Civano, Francesca, Reddy, Naveen A., Shapley, Alice E., Coil, Alison L., Mobasher, Bahram, Siana, Brian, Aird, James, Azadi, Mojegan, Freeman, William R., Leung, Gene C. K., Price, Sedona H., Fetherolf, Tara, Zick, Tom, and Barro, Guillermo. 2019. "The MOSDEF Survey: The Metallicity Dependence of X-Ray Binary Populations at z ̃ 2." The Astrophysical Journal 885: 65. https://doi.org/10.3847/1538-4357/ab4653
ID: 154601
Type: article
Authors: Fornasini, Francesca M.; Kriek, Mariska; Sanders, Ryan L.; Shivaei, Irene; Civano, Francesca; Reddy, Naveen A.; Shapley, Alice E.; Coil, Alison L.; Mobasher, Bahram; Siana, Brian; Aird, James; Azadi, Mojegan; Freeman, William R.; Leung, Gene C. K.; Price, Sedona H.; Fetherolf, Tara; Zick, Tom; Barro, Guillermo
Keywords: SAO
Abstract: Population synthesis models predict that high-mass X-ray binary (HMXB) populations produced in low-metallicity environments should be more X-ray luminous, a trend supported by studies of nearby galaxies. This trend may be responsible for the observed increase of the X-ray luminosity (L X) per star formation rate (SFR) with redshift due to the decrease of metallicity (Z) at fixed stellar mass as a function of redshift. To test this hypothesis, we use a sample of 79 z ̃ 2 star-forming galaxies with oxygen abundance measurements from the MOSDEF survey, which obtained rest-frame optical spectra for ̃1500 galaxies in the CANDELS fields at 1.37 ) per star formation rate (SFR) with redshift due to the decrease of metallicity (Z) at fixed stellar mass as a function of redshift. To test this hypothesis, we use a sample of 79 z ̃ 2 star-forming galaxies with oxygen abundance measurements from the MOSDEF survey, which obtained rest-frame optical spectra for ̃1500 galaxies in the CANDELS fields at 1.37 ) per star formation rate (SFR) with redshift due to the decrease of metallicity (Z) at fixed stellar mass as a function of redshift. To test this hypothesis, we use a sample of 79 z ̃ 2 star-forming galaxies with oxygen abundance measurements from the MOSDEF survey, which obtained rest-frame optical spectra for ̃1500 galaxies in the CANDELS fields at 1.37 X/SFR of our z ̃ 2 galaxy sample is enhanced by ≈0.4-0.8 dex relative to local HMXB L X-SFR scaling relations. Splitting our sample by Z, we find that L X/SFR and Z are anticorrelated with 97% confidence. This observed Z dependence for HMXB-dominated galaxies is consistent with both the local L X-SFR-Z relation and a subset of population synthesis models. Although the statistical significance of the observed trends is weak owing to the low X-ray statistics, these results constitute the first direct evidence connecting the redshift evolution of L X/SFR and the Z dependence of HMXBs.
Five decades observing Earth's atmospheric trace gases using ultraviolet and visible backscatter solar radiation from spaceGonzalez Abad, GonzaloSouri, Amir HosseinBak, JuseonChance, KellyFlynn, Lawrence E.Krotkov, Nickolay A.Lamsal, LokLi, CanLiu, XiongChan Miller, ChristopherNowlan, Caroline R.Suleiman, RaidWang, Huiqun2019DOI: info:10.1016/j.jqsrt.2019.04.030Journal of Quantitative Spectroscopy and Radiative Transferv. 238 106478 1064780022-4073
Gonzalez Abad, Gonzalo, Souri, Amir Hossein, Bak, Juseon, Chance, Kelly, Flynn, Lawrence E., Krotkov, Nickolay A., Lamsal, Lok, Li, Can, Liu, Xiong, Chan Miller, Christopher, Nowlan, Caroline R., Suleiman, Raid, and Wang, Huiqun. 2019. "Five decades observing Earth's atmospheric trace gases using ultraviolet and visible backscatter solar radiation from space." Journal of Quantitative Spectroscopy and Radiative Transfer 238: 106478. https://doi.org/10.1016/j.jqsrt.2019.04.030
ID: 154602
Type: article
Authors: Gonzalez Abad, Gonzalo; Souri, Amir Hossein; Bak, Juseon; Chance, Kelly; Flynn, Lawrence E.; Krotkov, Nickolay A.; Lamsal, Lok; Li, Can; Liu, Xiong; Chan Miller, Christopher; Nowlan, Caroline R.; Suleiman, Raid; Wang, Huiqun
Keywords: SAO
Abstract: Over the last five decades, Earth's atmosphere has been extensively monitored from space using different spectral ranges. Early efforts were directed at improving weather forecasts with the first meteorological satellites launched in the 1960s. Soon thereafter, the intersection between weather, climate and atmospheric chemistry led to the observation of atmospheric composition from space. During the 1970s the Nimbus satellite program started regular monitoring of ozone integrated columns and water vapor profiles using the Backscatter Ultraviolet Spectrometer, the Infrared Interferometer Spectrometer and the Satellite Infrared Spectrometer instruments. Five decades after these pioneer efforts, continuous progress in instrument design, and retrieval techniques allow researchers to monitor tropospheric concentrations of a wide range of species with implications for air quality, climate and weather. The time line of historic, present and future space-borne instruments measuring ultraviolet and visible backscattered solar radiation designed to quantify atmospheric trace gases is presented. We describe the instruments technological evolution and the basic concepts of retrieval theory. We include a review of algorithms developed for ozone, nitrogen dioxide, sulfur dioxide, formaldehyde, bromine monoxide, water vapor and glyoxal, a selection of studies using these algorithms, the challenges they face and how these challenges can be addressed. The paper ends by providing insights on the opportunities that new instruments will bring to the atmospheric chemistry, weather and air quality communities and how to address the pressing need for long-term, inter-calibrated data records necessary to monitor the response of the atmosphere to rapidly changing ecosystems.
Characterizing Magnetic Field Morphologies in Three Serpens Protostellar Cores with ALMALe Gouellec, Valentin J. M.Hull, Charles L. H.Maury, Anaëlle J.Girart, Josep M.Tychoniec, ŁukaszKristensen, Lars E.Li, Zhi-YunLouvet, FabienCortes, Paulo C.Rao, Ramprasad2019DOI: info:10.3847/1538-4357/ab43c2The Astrophysical Journalv. 885 106 1060004-637X
Le Gouellec, Valentin J. M., Hull, Charles L. H., Maury, Anaëlle J., Girart, Josep M., Tychoniec, Łukasz, Kristensen, Lars E., Li, Zhi-Yun, Louvet, Fabien, Cortes, Paulo C., and Rao, Ramprasad. 2019. "Characterizing Magnetic Field Morphologies in Three Serpens Protostellar Cores with ALMA." The Astrophysical Journal 885: 106. https://doi.org/10.3847/1538-4357/ab43c2
ID: 154603
Type: article
Authors: Le Gouellec, Valentin J. M.; Hull, Charles L. H.; Maury, Anaëlle J.; Girart, Josep M.; Tychoniec, Łukasz; Kristensen, Lars E.; Li, Zhi-Yun; Louvet, Fabien; Cortes, Paulo C.; Rao, Ramprasad
Keywords: SAO
Abstract: With the aim of characterizing the dynamical processes involved in the formation of young protostars, we present high-angular-resolution ALMA dust polarization observations of the Class 0 protostellar cores Serpens SMM1, Emb 8(N), and Emb 8. With spatial resolutions ranging from 150 to 40 au at 870 μm, we find unexpectedly high values of the polarization fraction along the outflow cavity walls in Serpens Emb 8(N). We use 3 mm and 1 mm molecular tracers to investigate outflow and dense-gas properties and their correlation with the polarization. These observations allow us to investigate the physical processes involved in the radiative alignment torques (RATs) acting on dust grains along the outflow cavity walls, which experience irradiation from accretion processes and outflow shocks. The inner core of SMM1-a presents a polarization pattern with a poloidal magnetic field at the bases of the two lobes of the bipolar outflow. To the south of SMM1-a we see two polarized filaments, one of which seems to trace the redshifted outflow cavity wall. The other may be an accretion streamer of material infalling onto the central protostar. We propose that the polarized emission we see at millimeter wavelengths along the irradiated cavity walls can be reconciled with the expectations of RAT theory if the aligned grains present at <500 au scales in Class 0 envelopes have grown larger than the 0.1 μm size of dust grains in the interstellar medium. Our observations allow us to constrain the magnetic field morphologies of star-forming sources within the central cores, along the outflow cavity walls, and in possible accretion streamers.
Trigonometric Parallaxes of High-mass Star-forming Regions: Our View of the Milky WayReid, Mark J.Menten, K. M.Brunthaler, A.Zheng, X. W.Dame, Thomas M.Xu, Y.Li, J.Sakai, N.Wu, Y.Immer, K.Zhang, B.Sanna, A.Moscadelli, L.Rygl, K. L. J.Bartkiewicz, A.Hu, B.Quiroga-Nuñez, L. H.van Langevelde, H. J.2019DOI: info:10.3847/1538-4357/ab4a11The Astrophysical Journalv. 885 131 1310004-637X
Reid, Mark J., Menten, K. M., Brunthaler, A., Zheng, X. W., Dame, Thomas M., Xu, Y., Li, J., Sakai, N., Wu, Y., Immer, K., Zhang, B., Sanna, A., Moscadelli, L., Rygl, K. L. J., Bartkiewicz, A., Hu, B., Quiroga-Nuñez, L. H., and van Langevelde, H. J. 2019. "Trigonometric Parallaxes of High-mass Star-forming Regions: Our View of the Milky Way." The Astrophysical Journal 885: 131. https://doi.org/10.3847/1538-4357/ab4a11
ID: 154604
Type: article
Authors: Reid, Mark J.; Menten, K. M.; Brunthaler, A.; Zheng, X. W.; Dame, Thomas M.; Xu, Y.; Li, J.; Sakai, N.; Wu, Y.; Immer, K.; Zhang, B.; Sanna, A.; Moscadelli, L.; Rygl, K. L. J.; Bartkiewicz, A.; Hu, B.; Quiroga-Nuñez, L. H.; van Langevelde, H. J.
Keywords: SAO
Abstract: We compile and analyze approximately 200 trigonometric parallaxes and proper motions of molecular masers associated with very young high-mass stars. Most of the measurements come from the BeSSeL Survey using the VLBA and the Japanese VERA project. These measurements strongly suggest that the Milky Way is a four-arm spiral, with some extra arm segments and spurs. Fitting log-periodic spirals to the locations of the masers, allowing for "kinks" in the spirals and using well-established arm tangencies in the fourth Galactic quadrant, allows us to significantly expand our view of the structure of the Milky Way. We present an updated model for its spiral structure and incorporate it into our previously published parallax-based distance-estimation program for sources associated with spiral arms. Modeling the three-dimensional space motions yields estimates of the distance to the Galactic center, {R}0=8.15+/- 0.15 {kpc}, the circular rotation speed at the Sun's position, {{{\Theta }}}0=236+/- 7 km s-1, and the nature of the rotation curve. Our data strongly constrain the full circular velocity of the Sun, {{{\Theta }}}0+{V}=247+/- 4 km s-1, and its angular velocity, ({{{\Theta }}}0+{V})/{R}0=30.32+/- 0.27 km s-1 kpc-1. Transforming the measured space motions to a Galactocentric frame which rotates with the Galaxy, we find non- circular velocity components typically ≲10 km s-1. However, near the Galactic bar and in a portion of the Perseus arm we find significantly larger non-circular motions. Young high-mass stars within 7 kpc of the Galactic center have a scale height of only 19 pc, and thus are well suited to define the Galactic plane. We find that the orientation of the plane is consistent with the IAU-defined plane to within ±0.°1, and that the Sun is offset toward the north Galactic pole by {Z}=5.5+/- 5.8 pc. Accounting for this offset places the central supermassive black hole, Sgr A*, in the midplane of the Galaxy. The measured motions perpendicular to the plane of the Galaxy limit precession of the plane to ≲4 km s-1 at the radius of the Sun. Using our improved Galactic parameters, we predict the Hulse-Taylor binary pulsar to be at a distance of 6.54 ± 0.24 kpc, assuming its orbital decay from gravitational radiation follows general relativity.
The Sloan Digital Sky Survey Reverberation Mapping Project: Accretion and Broad Emission Line Physics from a Hypervariable QuasarDexter, JasonXin, ShuoShen, YueGrier, C. J.Liu, TengGezari, SuviMcGreer, Ian D.Brandt, W. N.Hall, P. B.Horne, KeithSimm, TorbenMerloni, AndreaGreen, Paul J.Vivek, M.Trump, Jonathan R.Homayouni, YasamanPeterson, B. M.Schneider, Donald P.Kinemuchi, K.Pan, KaikeBizyaev, Dmitry2019DOI: info:10.3847/1538-4357/ab4354The Astrophysical Journalv. 885 44 440004-637X
Dexter, Jason, Xin, Shuo, Shen, Yue, Grier, C. J., Liu, Teng, Gezari, Suvi, McGreer, Ian D., Brandt, W. N., Hall, P. B., Horne, Keith, Simm, Torben, Merloni, Andrea, Green, Paul J., Vivek, M., Trump, Jonathan R., Homayouni, Yasaman, Peterson, B. M., Schneider, Donald P., Kinemuchi, K., Pan, Kaike, and Bizyaev, Dmitry. 2019. "The Sloan Digital Sky Survey Reverberation Mapping Project: Accretion and Broad Emission Line Physics from a Hypervariable Quasar." The Astrophysical Journal 885: 44. https://doi.org/10.3847/1538-4357/ab4354
ID: 154605
Type: article
Authors: Dexter, Jason; Xin, Shuo; Shen, Yue; Grier, C. J.; Liu, Teng; Gezari, Suvi; McGreer, Ian D.; Brandt, W. N.; Hall, P. B.; Horne, Keith; Simm, Torben; Merloni, Andrea; Green, Paul J.; Vivek, M.; Trump, Jonathan R.; Homayouni, Yasaman; Peterson, B. M.; Schneider, Donald P.; Kinemuchi, K.; Pan, Kaike; Bizyaev, Dmitry
Keywords: SAO
Abstract: We analyze extensive spectroscopic and photometric data of the hypervariable quasar SDSS J141324+530527 (RMID 017) at z = 0.456, an optical "changing-look" quasar from the Sloan Digital Sky Survey Reverberation Mapping project that increased in optical luminosity by a factor ≃10 between 2014 and 2017. The observed broad emission lines all respond in luminosity and width to the changing optical continuum, as expected for photoionization in a stratified, virialized broad emission line region. The luminosity changes therefore result from intrinsic changes in accretion power rather than variable obscuration. The variability is continuous and apparently stochastic, disfavoring an origin as a discrete event such as a tidal disruption flare or microlensing event. It is coordinated on day timescales with blue leading red, consistent with reprocessing powering the entire optical spectral energy distribution. We show that this process cannot work in a standard thin disk geometry on energetic grounds, and would instead require a large covering factor reprocessor. Disk instability models could potentially also explain the data, provided that the instability sets in near the inner radius of a geometrically thick accretion disk.
Brown dwarf census with the Dark Energy Survey year 3 data and the thin disc scale height of early L typesCarnero Rosell, A.Santiago, B.dal Ponte, M.Burningham, B.da Costa, L. N.James, David J.Marshall, J. L.McMahon, R. G.Bechtol, K.De Paris, L.Li, T.Pieres, A.García-Bellido, J.Abbott, T. M. C.Annis, J.Avila, S.Bernstein, G. M.Brooks, D.Burke, D. L.Carrasco Kind, M.Carretero, J.De Vicente, J.Drlica-Wagner, A.Fosalba, P.Frieman, J.Gaztanaga, E.Gruendl, R. A.Gschwend, J.Gutierrez, G.Hollowood, D. L.Maia, M. A. G.Menanteau, F.Miquel, R.Plazas, A. A.Roodman, A.Sanchez, E.Scarpine, V.Schindler, R.Serrano, S.Sevilla-Noarbe, I.Smith, M.Sobreira, F.Soares-Santos, M.Suchyta, E.Swanson, M. E. C.Tarle, G.Vikram, V.Walker, A. R.DES Collaboration2019DOI: info:10.1093/mnras/stz2398Monthly Notices of the Royal Astronomical Societyv. 489 5301 53255301–53250035-8711
Carnero Rosell, A., Santiago, B., dal Ponte, M., Burningham, B., da Costa, L. N., James, David J., Marshall, J. L., McMahon, R. G., Bechtol, K., De Paris, L., Li, T., Pieres, A., García-Bellido, J., Abbott, T. M. C., Annis, J., Avila, S., Bernstein, G. M., Brooks, D., Burke, D. L., Carrasco Kind, M., Carretero, J., De Vicente, J., Drlica-Wagner, A., Fosalba, P., Frieman, J. et al. 2019. "Brown dwarf census with the Dark Energy Survey year 3 data and the thin disc scale height of early L types." Monthly Notices of the Royal Astronomical Society 489: 5301– 5325. https://doi.org/10.1093/mnras/stz2398
ID: 154606
Type: article
Authors: Carnero Rosell, A.; Santiago, B.; dal Ponte, M.; Burningham, B.; da Costa, L. N.; James, David J.; Marshall, J. L.; McMahon, R. G.; Bechtol, K.; De Paris, L.; Li, T.; Pieres, A.; García-Bellido, J.; Abbott, T. M. C.; Annis, J.; Avila, S.; Bernstein, G. M.; Brooks, D.; Burke, D. L.; Carrasco Kind, M.; Carretero, J.; De Vicente, J.; Drlica-Wagner, A.; Fosalba, P.; Frieman, J.; Gaztanaga, E.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Hollowood, D. L.; Maia, M. A. G.; Menanteau, F.; Miquel, R.; Plazas, A. A.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schindler, R.; Serrano, S.; Sevilla-Noarbe, I.; Smith, M.; Sobreira, F.; Soares-Santos, M.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Vikram, V.; Walker, A. R.; DES Collaboration
Keywords: SAO
Abstract: In this paper we present a catalogue of 11 745 brown dwarfs with spectral types ranging from L0 to T9, photometrically classified using data from the Dark Energy Survey (DES) year 3 release matched to the Vista Hemisphere Survey (VHS) DR3 and Wide-field Infrared Survey Explorer (WISE) data, covering ≈2400 deg2 up to iAB = 22. The classification method follows the same phototype method previously applied to SDSS-UKIDSS-WISE data. The most significant difference comes from the use of DES data instead of SDSS, which allow us to classify almost an order of magnitude more brown dwarfs than any previous search and reaching distances beyond 400 pc for the earliest types. Next, we also present and validate the GalmodBD simulation, which produces brown dwarf number counts as a function of structural parameters with realistic photometric properties of a given survey. We use this simulation to estimate the completeness and purity of our photometric LT catalogue down to iAB = 22, as well as to compare to the observed number of LT types. We put constraints on the thin disc scale height for the early L (L0-L3) population to be around 450 pc, in agreement with previous findings. For completeness, we also publish in a separate table a catalogue of 20 863 M dwarfs that passed our colour cut with spectral types greater than M6. Both the LT and the late M catalogues are found at DES release page https://des.ncsa.illinois.edu/releases/other/y3-mlt.
Anatomy of a Cooling Flow: The Feedback Response to Pure Cooling in the Core of the Phoenix ClusterMcDonald, M.McNamara, B. R.Voit, G. M.Bayliss, M.Benson, B. A.Brodwin, M.Canning, R. E. A.Florian, M. K.Garmire, G. P.Gaspari, M.Gladders, M. D.Hlavacek-Larrondo, J.Kara, E.Reichardt, C. L.Russell, H. R.Saro, A.Sharon, K.Somboonpanyakul, T.Tremblay, Grant R.van Weeren, R. J.2019DOI: info:10.3847/1538-4357/ab464cThe Astrophysical Journalv. 885 63 630004-637X
McDonald, M., McNamara, B. R., Voit, G. M., Bayliss, M., Benson, B. A., Brodwin, M., Canning, R. E. A., Florian, M. K., Garmire, G. P., Gaspari, M., Gladders, M. D., Hlavacek-Larrondo, J., Kara, E., Reichardt, C. L., Russell, H. R., Saro, A., Sharon, K., Somboonpanyakul, T., Tremblay, Grant R., and van Weeren, R. J. 2019. "Anatomy of a Cooling Flow: The Feedback Response to Pure Cooling in the Core of the Phoenix Cluster." The Astrophysical Journal 885: 63. https://doi.org/10.3847/1538-4357/ab464c
ID: 154607
Type: article
Authors: McDonald, M.; McNamara, B. R.; Voit, G. M.; Bayliss, M.; Benson, B. A.; Brodwin, M.; Canning, R. E. A.; Florian, M. K.; Garmire, G. P.; Gaspari, M.; Gladders, M. D.; Hlavacek-Larrondo, J.; Kara, E.; Reichardt, C. L.; Russell, H. R.; Saro, A.; Sharon, K.; Somboonpanyakul, T.; Tremblay, Grant R.; van Weeren, R. J.
Keywords: SAO
Abstract: We present new, deep observations of the Phoenix cluster from Chandra, the Hubble Space Telescope, and the Karl Jansky Very Large Array. These data provide an order-of-magnitude improvement in depth and/or angular resolution over previous observations at X-ray, optical, and radio wavelengths. We find that the one-dimensional temperature and entropy profiles are consistent with expectations for pure-cooling models. In particular, the entropy profile is well fit by a single power law at all radii, with no evidence for excess entropy in the core. In the inner ∼10 kpc, the cooling time is shorter than any other known cluster by an order of magnitude, while the ratio of the cooling time to freefall time (t cool/t ff) approaches unity, signaling that the intracluster medium is unable to resist multiphase condensation on kpc scales. The bulk of the cooling in the inner ∼20 kpc is confined to a low-entropy filament extending northward from the central galaxy, with t cool/t ff ∼ 1 over the length of the filament. In this filament, we find evidence for ∼1010 M in cool (∼104 K) gas (as traced by the [O II]λλ3726,3729 doublet), which is coincident with the low-entropy filament and absorbing soft X-rays. The bulk of this cool gas is draped around and behind a pair of X-ray cavities, presumably bubbles that have been inflated by radio jets. These data support a picture in which active galactic nucleus feedback is promoting the formation of a multiphase medium via uplift of low-entropy gas, either via ordered or chaotic (turbulent) motions.
Dynamical Masses for the Triple System HD 28363 in the Hyades ClusterTorres, GuillermoStefanik, Robert P.Latham, David W.2019DOI: info:10.3847/1538-4357/ab43e2The Astrophysical Journalv. 885 9 90004-637X
Torres, Guillermo, Stefanik, Robert P., and Latham, David W. 2019. "Dynamical Masses for the Triple System HD 28363 in the Hyades Cluster." The Astrophysical Journal 885: 9. https://doi.org/10.3847/1538-4357/ab43e2
ID: 154608
Type: article
Authors: Torres, Guillermo; Stefanik, Robert P.; Latham, David W.
Keywords: SAO
Abstract: The star HD 28363 in the Hyades cluster has been known for over a century as a visual binary with a period of 40 yr. The secondary is, in turn, a single-lined spectroscopic binary with a 21 day period. Here we report extensive spectroscopic monitoring of this hierarchical triple system that reveals the spectral lines of the third star for the first time. Combined with astrometric information, this makes it possible to determine the dynamical masses of all three stars. Only six other binaries in the Hyades have had their individual component masses determined dynamically. We infer the properties of the system by combining our radial-velocity measurements with visual observations, lunar occultation measurements, and with proper motions from the Hipparcos and Gaia missions that provide a constraint on the astrometric acceleration. We derive a mass of {1.341}-0.024+0.026 {M} for the visual primary, and 1.210 ± 0.021 and 0.781 ± 0.014 M for the other two stars. These measurements along with those for the other six systems establish an empirical mass-luminosity relation in the Hyades that is in broad agreement with current models of stellar evolution for the known age and chemical composition of the cluster.
Ubiquitous cold and massive filaments in cool core clustersOlivares, V.Salome, P.Combes, F.Hamer, S.Guillard, P.Lehnert, M. D.Polles, F. L.Beckmann, R. S.Dubois, Y.Donahue, M.Edge, A.Fabian, A. C.McNamara, B.Rose, T.Russell, H. R.Tremblay, GrantVantyghem, A.Canning, R. E. A.Ferland, G.Godard, B.Peirani, S.Pineau des Forets, G.2019DOI: info:10.1051/0004-6361/201935350Astronomy and Astrophysicsv. 631 A22 A220004-6361
Olivares, V., Salome, P., Combes, F., Hamer, S., Guillard, P., Lehnert, M. D., Polles, F. L., Beckmann, R. S., Dubois, Y., Donahue, M., Edge, A., Fabian, A. C., McNamara, B., Rose, T., Russell, H. R., Tremblay, Grant, Vantyghem, A., Canning, R. E. A., Ferland, G., Godard, B., Peirani, S., and Pineau des Forets, G. 2019. "Ubiquitous cold and massive filaments in cool core clusters." Astronomy and Astrophysics 631: A22. https://doi.org/10.1051/0004-6361/201935350
ID: 154609
Type: article
Authors: Olivares, V.; Salome, P.; Combes, F.; Hamer, S.; Guillard, P.; Lehnert, M. D.; Polles, F. L.; Beckmann, R. S.; Dubois, Y.; Donahue, M.; Edge, A.; Fabian, A. C.; McNamara, B.; Rose, T.; Russell, H. R.; Tremblay, Grant; Vantyghem, A.; Canning, R. E. A.; Ferland, G.; Godard, B.; Peirani, S.; Pineau des Forets, G.
Keywords: SAO
Abstract: Multi-phase filamentary structures around brightest cluster galaxies (BCG) are likely a key step of AGN-feedback. We observed molecular gas in three cool cluster cores, namely Centaurus, Abell S1101, and RXJ1539.5, and gathered ALMA (Atacama Large Millimeter/submillimeter Array) and MUSE (Multi Unit Spectroscopic Explorer) data for 12 other clusters. Those observations show clumpy, massive, and long (3-25 kpc) molecular filaments, preferentially located around the radio bubbles inflated by the AGN. Two objects show nuclear molecular disks. The optical nebula is certainly tracing the warm envelopes of cold molecular filaments. Surprisingly, the radial profile of the Hα/CO flux ratio is roughly constant for most of the objects, suggesting that (i) between 1.2 and 6 times more cold gas could be present and (ii) local processes must be responsible for the excitation. Projected velocities are between 100 and 400 km s-1, with disturbed kinematics and sometimes coherent gradients. This is likely due to the mixing in projection of several thin (and as yet) unresolved filaments. The velocity fields may be stirred by turbulence induced by bubbles, jets, or merger-induced sloshing. Velocity and dispersions are low, below the escape velocity. Cold clouds should eventually fall back and fuel the AGN. We compare the radial extent of the filaments, rfil, with the region where the X-ray gas can become thermally unstable. The filaments are always inside the low-entropy and short-cooling-time region, where tcool/tff cool/tff of 8-23 at rfil, is likely due to (i) a more complex gravitational potential affecting the free- fall time tff (sloshing, mergers, etc.) and (ii) the presence of inhomogeneities or uplifted gas in the ICM, affecting the cooling time tcool. For some of the sources, rfil lies where the ratio of the cooling time to the eddy-turnover time, tcool/teddy, is approximately unity.
Signatures of Tidal Disruption in Ultra-faint Dwarf Galaxies: A Combined HST, Gaia, and MMT/Hectochelle Study of Leo VMutlu-Pakdil, BurçinSand, David J.Walker, Matthew G.Caldwell, NelsonCarlin, Jeffrey L.Collins, Michelle L.Crnojević, DenijaMateo, MarioOlszewski, Edward W.Seth, Anil C.Strader, JayWillman, BethZaritsky, Dennis2019DOI: info:10.3847/1538-4357/ab45ecThe Astrophysical Journalv. 885 53 530004-637X
Mutlu-Pakdil, Burçin, Sand, David J., Walker, Matthew G., Caldwell, Nelson, Carlin, Jeffrey L., Collins, Michelle L., Crnojević, Denija, Mateo, Mario, Olszewski, Edward W., Seth, Anil C., Strader, Jay, Willman, Beth, and Zaritsky, Dennis. 2019. "Signatures of Tidal Disruption in Ultra-faint Dwarf Galaxies: A Combined HST, Gaia, and MMT/Hectochelle Study of Leo V." The Astrophysical Journal 885: 53. https://doi.org/10.3847/1538-4357/ab45ec
ID: 154610
Type: article
Authors: Mutlu-Pakdil, Burçin; Sand, David J.; Walker, Matthew G.; Caldwell, Nelson; Carlin, Jeffrey L.; Collins, Michelle L.; Crnojević, Denija; Mateo, Mario; Olszewski, Edward W.; Seth, Anil C.; Strader, Jay; Willman, Beth; Zaritsky, Dennis
Keywords: SAO
Abstract: The ultra-faint dwarf galaxy Leo V has shown both photometric overdensities and kinematic members at large radii, along with a tentative kinematic gradient, suggesting that it may have undergone a close encounter with the Milky Way. We investigate these signs of disruption through a combination of (i) high precision photometry obtained with the Hubble Space Telescope (HST), (ii) two epochs of stellar spectra obtained with the Hectochelle Spectrograph on the MMT, and (iii) measurements from the Gaia mission. Using the HST data, we examine one of the reported stream-like overdensities at large radii, and conclude that it is not a true stellar stream, but instead a clump of foreground stars and background galaxies. Our spectroscopic analysis shows that one known member star is likely a binary, and challenges the membership status of three others, including two distant candidates that had formerly provided evidence for overall stellar mass loss. We also find evidence that the proposed kinematic gradient across Leo V might be due to small number statistics. We update the systemic proper motion of Leo V, finding ({μ }α \cos δ ,{μ }δ )=(0.009+/- 0.560, -0.777 ± 0.314) mas yr-1, which is consistent with its reported orbit that did not put Leo V at risk of being disturbed by the Milky Way. These findings remove most of the observational clues that suggested Leo V was disrupting; however, we also find new plausible member stars, two of which are located >5 half-light radii from the main body. These stars require further investigation. Therefore, the nature of Leo V still remains an open question.
Dark Energy Survey Year 1 results: constraints on intrinsic alignments and their colour dependence from galaxy clustering and weak lensingSamuroff, S.Blazek, J.Troxel, M. A.MacCrann, N.Krause, E.Leonard, C. D.Prat, J.Gruen, D.Dodelson, S.Eifler, T. F.Gatti, M.Hartley, W. G.Hoyle, B.Larsen, P.Zuntz, J.Abbott, T. M. C.Allam, S.Annis, J.Bernstein, G. M.Bertin, E.Bridle, S. L.Brooks, D.Carnero Rosell, A.Carrasco Kind, M.Carretero, J.Castander, F. J.Cunha, C. E.da Costa, L. N.Davis, C.De Vicente, J.DePoy, D. L.Desai, S.Diehl, H. T.Dietrich, J. P.Doel, P.Flaugher, B.Fosalba, P.Frieman, J.García-Bellido, J.Gaztanaga, E.Gerdes, D. W.Gruendl, R. A.Gschwend, J.Gutierrez, G.Hollowood, D. L.Honscheid, K.James, David J.Kuehn, K.Kuropatkin, N.Lima, M.Maia, M. A. G.March, M.Marshall, J. L.Martini, P.Melchior, P.Menanteau, F.Miller, C. J.Miquel, R.Ogando, R. L. C.Plazas, A. A.Sanchez, E.Scarpine, V.Schindler, R.Schubnell, M.Serrano, S.Sevilla-Noarbe, I.Sheldon, E.Smith, M.Sobreira, F.Suchyta, E.Tarle, G.Thomas, D.Vikram, V.DES Collaboration2019DOI: info:10.1093/mnras/stz2197Monthly Notices of the Royal Astronomical Societyv. 489 5453 54825453–54820035-8711
Samuroff, S., Blazek, J., Troxel, M. A., MacCrann, N., Krause, E., Leonard, C. D., Prat, J., Gruen, D., Dodelson, S., Eifler, T. F., Gatti, M., Hartley, W. G., Hoyle, B., Larsen, P., Zuntz, J., Abbott, T. M. C., Allam, S., Annis, J., Bernstein, G. M., Bertin, E., Bridle, S. L., Brooks, D., Carnero Rosell, A., Carrasco Kind, M., Carretero, J. et al. 2019. "Dark Energy Survey Year 1 results: constraints on intrinsic alignments and their colour dependence from galaxy clustering and weak lensing." Monthly Notices of the Royal Astronomical Society 489: 5453– 5482. https://doi.org/10.1093/mnras/stz2197
ID: 154611
Type: article
Authors: Samuroff, S.; Blazek, J.; Troxel, M. A.; MacCrann, N.; Krause, E.; Leonard, C. D.; Prat, J.; Gruen, D.; Dodelson, S.; Eifler, T. F.; Gatti, M.; Hartley, W. G.; Hoyle, B.; Larsen, P.; Zuntz, J.; Abbott, T. M. C.; Allam, S.; Annis, J.; Bernstein, G. M.; Bertin, E.; Bridle, S. L.; Brooks, D.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Castander, F. J.; Cunha, C. E.; da Costa, L. N.; Davis, C.; De Vicente, J.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gaztanaga, E.; Gerdes, D. W.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Hollowood, D. L.; Honscheid, K.; James, David J.; Kuehn, K.; Kuropatkin, N.; Lima, M.; Maia, M. A. G.; March, M.; Marshall, J. L.; Martini, P.; Melchior, P.; Menanteau, F.; Miller, C. J.; Miquel, R.; Ogando, R. L. C.; Plazas, A. A.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Serrano, S.; Sevilla-Noarbe, I.; Sheldon, E.; Smith, M.; Sobreira, F.; Suchyta, E.; Tarle, G.; Thomas, D.; Vikram, V.; DES Collaboration
Keywords: SAO
Abstract: We perform a joint analysis of intrinsic alignments and cosmology using tomographic weak lensing, galaxy clustering, and galaxy-galaxy lensing measurements from Year 1 (Y1) of the Dark Energy Survey. We define early- and late-type subsamples, which are found to pass a series of systematics tests, including for spurious photometric redshift error and point spread function correlations. We analyse these split data alongside the fiducial mixed Y1 sample using a range of intrinsic alignment models. In a fiducial non-linear alignment model analysis, assuming a flat Λ cold dark matter cosmology, we find a significant difference in intrinsic alignment amplitude, with early-type galaxies favouring A_IA = 2.38^{+0.32}_{-0.31} and late-type galaxies consistent with no intrinsic alignments at 0.05^{+0.10}_{-0.09}. The analysis is repeated using a number of extended model spaces, including a physically motivated model that includes both tidal torquing and tidal alignment mechanisms. In multiprobe likelihood chains in which cosmology, intrinsic alignments in both galaxy samples and all other relevant systematics are varied simultaneously, we find the tidal alignment and tidal torquing parts of the intrinsic alignment signal have amplitudes A_1 = 2.66 ^{+0.67}_{-0.66}, A_2=-2.94^{+1.94}_{-1.83}, respectively, for early-type galaxies and A_1 = 0.62 ^{+0.41}_{-0.41}, A_2 = -2.26^{+1.30}_{-1.16} for late-type galaxies. In the full (mixed) Y1 sample the best constraints are A_1 = 0.70 ^{+0.41}_{-0.38}, A_2 = -1.36 ^{+1.08}_{-1.41}. For all galaxy splits and IA models considered, we report cosmological parameter constraints consistent with the results of the main DES Y1 cosmic shear and multiprobe cosmology papers.
VLA cm-wave survey of young stellar objects in the Oph A cluster: constraining extreme UV- and X-ray-driven disk photoevaporation. A pathfinder for Square Kilometre Array studiesCoutens, A.Liu, H. B.Jiménez-Serra, I.Bourke, T. L.Forbrich, J.Hoare, M.Loinard, L.Testi, L.Audard, M.Caselli, P.Chacón-Tanarro, A.Codella, C.Di Francesco, J.Fontani, F.Hogerheijde, M.Johansen, A.Johnstone, D.Maddison, S.Panić, O.Pérez, L. M.Podio, L.Punanova, A.Rawlings, J. M. C.Semenov, D.Tazzari, M.Tobin, J. J.van der Wiel, M. H. D.van Langevelde, H. J.Vlemmings, W.Walsh, C.Wilner, David2019DOI: info:10.1051/0004-6361/201935340Astronomy and Astrophysicsv. 631 A58 A580004-6361
Coutens, A., Liu, H. B., Jiménez-Serra, I., Bourke, T. L., Forbrich, J., Hoare, M., Loinard, L., Testi, L., Audard, M., Caselli, P., Chacón-Tanarro, A., Codella, C., Di Francesco, J., Fontani, F., Hogerheijde, M., Johansen, A., Johnstone, D., Maddison, S., Panić, O., Pérez, L. M., Podio, L., Punanova, A., Rawlings, J. M. C., Semenov, D., Tazzari, M. et al. 2019. "VLA cm-wave survey of young stellar objects in the Oph A cluster: constraining extreme UV- and X-ray-driven disk photoevaporation. A pathfinder for Square Kilometre Array studies." Astronomy and Astrophysics 631: A58. https://doi.org/10.1051/0004-6361/201935340
ID: 154612
Type: article
Authors: Coutens, A.; Liu, H. B.; Jiménez-Serra, I.; Bourke, T. L.; Forbrich, J.; Hoare, M.; Loinard, L.; Testi, L.; Audard, M.; Caselli, P.; Chacón-Tanarro, A.; Codella, C.; Di Francesco, J.; Fontani, F.; Hogerheijde, M.; Johansen, A.; Johnstone, D.; Maddison, S.; Panić, O.; Pérez, L. M.; Podio, L.; Punanova, A.; Rawlings, J. M. C.; Semenov, D.; Tazzari, M.; Tobin, J. J.; van der Wiel, M. H. D.; van Langevelde, H. J.; Vlemmings, W.; Walsh, C.; Wilner, David
Keywords: SAO
Abstract: Observations of young stellar objects (YSOs) in centimeter bands can probe the continuum emission from growing dust grains, ionized winds, and magnetospheric activity that are intimately connected to the evolution of protoplanetary disks and the formation of planets. We carried out sensitive continuum observations toward the Ophiuchus A star-forming region, using the Karl G. Jansky Very Large Array (VLA) at 10 GHz over a field-of-view of 6' and with a spatial resolution of θmaj ×θmin 0.''4 × 0.''2. We achieved a 5 μJy beam-1 rms noise level at the center of our mosaic field of view. Among the 18 sources we detected, 16 were YSOs (three Class 0, five Class I, six Class II, and two Class III) and two were extragalactic candidates. We find that thermal dust emission generally contributed less than 30% of the emission at 10 GHz. The radio emission is dominated by other types of emission, such as gyro-synchrotron radiation from active magnetospheres, free-free emission from thermal jets, free-free emission from the outflowing photoevaporated disk material, and synchrotron emission from accelerated cosmic-rays in jet or protostellar surface shocks. These different types of emission could not be clearly disentangled. Our non-detections for Class II/III disks suggest that extreme UV-driven photoevaporation is insufficient to explain disk dispersal, assuming that the contribution of UV photoevaporating stellar winds to radio flux does not evolve over time. The sensitivity of our data cannot exclude photoevaporation due to the role of X-ray photons as an efficient mechanism for disk dispersal. Deeper surveys using the Square Kilometre Array (SKA) will have the capacity to provide significant constraints to disk photoevaporation. The mosaic image is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz- bin/cat/J/A+A/631/A58
Exoplanet characterisation in the longest known resonant chain: the K2-138 system seen by HARPSLopez, T. A.Barros, S. C. C.Santerne, A.Deleuil, M.Adibekyan, V.Almenara, J. -MArmstrong, D. J.Brugger, B.Barrado, D.Bayliss, D.Boisse, I.Bonomo, A. S.Bouchy, F.Brown, D. J. A.Carli, E.Demangeon, O.Dumusque, X.Díaz, R. F.Faria, J. P.Figueira, P.Foxell, E.Giles, H.Hébrard, G.Hojjatpanah, S.Kirk, JamesLillo-Box, J.Lovis, C.Mousis, O.da Nóbrega, H. J.Nielsen, L. D.Neal, J. J.Osborn, H. P.Pepe, F.Pollacco, D.Santos, N. C.Sousa, S. G.Udry, S.Vigan, A.Wheatley, P. J.2019DOI: info:10.1051/0004-6361/201936267Astronomy and Astrophysicsv. 631 A90 A900004-6361
Lopez, T. A., Barros, S. C. C., Santerne, A., Deleuil, M., Adibekyan, V., Almenara, J. -M, Armstrong, D. J., Brugger, B., Barrado, D., Bayliss, D., Boisse, I., Bonomo, A. S., Bouchy, F., Brown, D. J. A., Carli, E., Demangeon, O., Dumusque, X., Díaz, R. F., Faria, J. P., Figueira, P., Foxell, E., Giles, H., Hébrard, G., Hojjatpanah, S., Kirk, James et al. 2019. "Exoplanet characterisation in the longest known resonant chain: the K2-138 system seen by HARPS." Astronomy and Astrophysics 631: A90. https://doi.org/10.1051/0004-6361/201936267
ID: 154613
Type: article
Authors: Lopez, T. A.; Barros, S. C. C.; Santerne, A.; Deleuil, M.; Adibekyan, V.; Almenara, J. -M; Armstrong, D. J.; Brugger, B.; Barrado, D.; Bayliss, D.; Boisse, I.; Bonomo, A. S.; Bouchy, F.; Brown, D. J. A.; Carli, E.; Demangeon, O.; Dumusque, X.; Díaz, R. F.; Faria, J. P.; Figueira, P.; Foxell, E.; Giles, H.; Hébrard, G.; Hojjatpanah, S.; Kirk, James; Lillo-Box, J.; Lovis, C.; Mousis, O.; da Nóbrega, H. J.; Nielsen, L. D.; Neal, J. J.; Osborn, H. P.; Pepe, F.; Pollacco, D.; Santos, N. C.; Sousa, S. G.; Udry, S.; Vigan, A.; Wheatley, P. J.
Keywords: SAO
Abstract: The detection of low-mass transiting exoplanets in multiple systems brings new constraints to planetary formation and evolution processes and challenges the current planet formation theories. Nevertheless, only a mere fraction of the small planets detected by Kepler and K2 have precise mass measurements, which are mandatory to constrain their composition. We aim to characterise the planets that orbit the relatively bright star K2-138. This system is dynamically particular as it presents the longest chain known to date of planets close to the 3:2 resonance. We obtained 215 HARPS spectra from which we derived the radial-velocity variations of K2-138. Via a joint Bayesian analysis of both the K2 photometry and HARPS radial-velocities (RVs), we constrained the parameters of the six planets in orbit. The masses of the four inner planets, from b to e, are 3.1, 6.3, 7.9, and 13.0 M with a precision of 34, 20, 18, and 15%, respectively. The bulk densities are 4.9, 2.8, 3.2, and 1.8 g cm-3, ranging from Earth to Neptune- like values. For planets f and g, we report upper limits. Finally, we predict transit timing variations of the order two to six minutes from the masses derived. Given its peculiar dynamics, K2-138 is an ideal target for transit timing variation (TTV) measurements from space with the upcoming CHaracterizing ExOPlanet Satellite (CHEOPS) to study this highly-packed system and compare TTV and RV masses. Full Table A.3 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz- bin/cat/J/A+A/631/A90
A wide star-black-hole binary system from radial-velocity measurementsLiu, JifengZhang, HaotongHoward, Andrew W.Bai, ZhongruiLu, YoujunSoria, RobertoJustham, StephenLi, XiangdongZheng, ZhengWang, TingguiBelczynski, KrzysztofCasares, JorgeZhang, WeiYuan, HailongDong, YiqiaoLei, YajuanIsaacson, HowardWang, SongBai, YuShao, YongGao, QingWang, YilunNiu, ZexiCui, KaimingZheng, ChuanjieMu, XiaoyongZhang, LanWang, WeiHeger, AlexanderQi, ZhaoxiangLiao, ShilongLattanzi, MarioGu, Wei-MinWang, JunfengWu, JianfengShao, LijingShen, RongfengWang, XiaofengBregman, JoelDi Stefano, RosanneLiu, QingzhongHan, ZhanwenZhang, TianmengWang, HuijuanRen, JuanjuanZhang, JunboZhang, JujiaWang, XiaoliCabrera-Lavers, AntonioCorradi, RomanoRebolo, RafaelZhao, YonghengZhao, GangChu, YaoquanCui, Xiangqun2019DOI: info:10.1038/s41586-019-1766-2Naturev. 575 618 621618–6210028-0836
Liu, Jifeng, Zhang, Haotong, Howard, Andrew W., Bai, Zhongrui, Lu, Youjun, Soria, Roberto, Justham, Stephen, Li, Xiangdong, Zheng, Zheng, Wang, Tinggui, Belczynski, Krzysztof, Casares, Jorge, Zhang, Wei, Yuan, Hailong, Dong, Yiqiao, Lei, Yajuan, Isaacson, Howard, Wang, Song, Bai, Yu, Shao, Yong, Gao, Qing, Wang, Yilun, Niu, Zexi, Cui, Kaiming, Zheng, Chuanjie et al. 2019. "A wide star-black-hole binary system from radial-velocity measurements." Nature 575: 618– 621. https://doi.org/10.1038/s41586-019-1766-2
ID: 154614
Type: article
Authors: Liu, Jifeng; Zhang, Haotong; Howard, Andrew W.; Bai, Zhongrui; Lu, Youjun; Soria, Roberto; Justham, Stephen; Li, Xiangdong; Zheng, Zheng; Wang, Tinggui; Belczynski, Krzysztof; Casares, Jorge; Zhang, Wei; Yuan, Hailong; Dong, Yiqiao; Lei, Yajuan; Isaacson, Howard; Wang, Song; Bai, Yu; Shao, Yong; Gao, Qing; Wang, Yilun; Niu, Zexi; Cui, Kaiming; Zheng, Chuanjie; Mu, Xiaoyong; Zhang, Lan; Wang, Wei; Heger, Alexander; Qi, Zhaoxiang; Liao, Shilong; Lattanzi, Mario; Gu, Wei-Min; Wang, Junfeng; Wu, Jianfeng; Shao, Lijing; Shen, Rongfeng; Wang, Xiaofeng; Bregman, Joel; Di Stefano, Rosanne; Liu, Qingzhong; Han, Zhanwen; Zhang, Tianmeng; Wang, Huijuan; Ren, Juanjuan; Zhang, Junbo; Zhang, Jujia; Wang, Xiaoli; Cabrera-Lavers, Antonio; Corradi, Romano; Rebolo, Rafael; Zhao, Yongheng; Zhao, Gang; Chu, Yaoquan; Cui, Xiangqun
Keywords: SAO
Abstract: All stellar-mass black holes have hitherto been identified by X-rays emitted from gas that is accreting onto the black hole from a companion star. These systems are all binaries with a black-hole mass that is less than 30 times that of the Sun1-4. Theory predicts, however, that X-ray-emitting systems form a minority of the total population of star-black-hole binaries5,6. When the black hole is not accreting gas, it can be found through radial-velocity measurements of the motion of the companion star. Here we report radial-velocity measurements taken over two years of the Galactic B-type star, LB-1. We find that the motion of the B star and an accompanying Hα emission line require the presence of a dark companion with a mass of 68-13+11 solar masses, which can only be a black hole. The long orbital period of 78.9 days shows that this is a wide binary system. Gravitational-wave experiments have detected black holes of similar mass, but the formation of such massive ones in a high- metallicity environment would be extremely challenging within current stellar evolution theories.
Evolution of the Stellar Mass-Metallicity Relation. II. Constraints on Galactic Outflows from the Mg Abundances of Quiescent GalaxiesLeethochawalit, NichaKirby, Evan N.Ellis, Richard S.Moran, Sean M.Treu, Tommaso2019DOI: info:10.3847/1538-4357/ab4809The Astrophysical Journalv. 885 100 1000004-637X
Leethochawalit, Nicha, Kirby, Evan N., Ellis, Richard S., Moran, Sean M., and Treu, Tommaso. 2019. "Evolution of the Stellar Mass-Metallicity Relation. II. Constraints on Galactic Outflows from the Mg Abundances of Quiescent Galaxies." The Astrophysical Journal 885: 100. https://doi.org/10.3847/1538-4357/ab4809
ID: 154615
Type: article
Authors: Leethochawalit, Nicha; Kirby, Evan N.; Ellis, Richard S.; Moran, Sean M.; Treu, Tommaso
Keywords: SAO
Abstract: We present the stellar mass-[Fe/H] and mass-[Mg/H] relation of quiescent galaxies in two galaxy clusters at z ̃ 0.39 and z ̃ 0.54. We derive the age, [Fe/H], and [Mg/Fe] for each individual galaxy using a full- spectrum fitting technique. By comparing with the relations for z ̃ 0 Sloan Digital Sky Survey galaxies, we confirm our previous finding that the mass-[Fe/H] relation evolves with redshift. The mass-[Fe/H] relation at higher redshift has lower normalization and possibly steeper slope. However, based on our sample, the mass-[Mg/H] relation does not evolve over the observed redshift range. We use a simple analytic chemical evolution model to constrain the average outflow that these galaxies experience over their lifetime, via the calculation of mass-loading factor. We find that the average mass-loading factor η is a power-law function of galaxy stellar mass, η \propto {M}* -0.21+/- 0.09. The measured mass-loading factors are consistent with the results of other observational methods for outflow measurements and with the predictions where outflow is caused by star formation feedback in turbulent disks.
A common origin for dynamically associated near-Earth asteroid pairsMoskovitz, Nicholas A.Fatka, PetrFarnocchia, DavideDevogèle, MaximePolishook, DavidThomas, Cristina A.Mommert, MichaelAvner, Louis D.Binzel, Richard P.Burt, BrianChristensen, EricDemeo, FrancescaHinkle, MaryHora, Joseph L.Magnusson, MitchellMatson, RobertPerson, MichaelSkiff, BrianThirouin, AudreyTrilling, DavidWasserman, Lawrence H.Willman, Mark2019DOI: info:10.1016/j.icarus.2019.05.030Icarusv. 333 165 176165–1760019-1035
Moskovitz, Nicholas A., Fatka, Petr, Farnocchia, Davide, Devogèle, Maxime, Polishook, David, Thomas, Cristina A., Mommert, Michael, Avner, Louis D., Binzel, Richard P., Burt, Brian, Christensen, Eric, Demeo, Francesca, Hinkle, Mary, Hora, Joseph L., Magnusson, Mitchell, Matson, Robert, Person, Michael, Skiff, Brian, Thirouin, Audrey, Trilling, David, Wasserman, Lawrence H., and Willman, Mark. 2019. "A common origin for dynamically associated near-Earth asteroid pairs." Icarus 333: 165– 176. https://doi.org/10.1016/j.icarus.2019.05.030
ID: 154616
Type: article
Authors: Moskovitz, Nicholas A.; Fatka, Petr; Farnocchia, Davide; Devogèle, Maxime; Polishook, David; Thomas, Cristina A.; Mommert, Michael; Avner, Louis D.; Binzel, Richard P.; Burt, Brian; Christensen, Eric; Demeo, Francesca; Hinkle, Mary; Hora, Joseph L.; Magnusson, Mitchell; Matson, Robert; Person, Michael; Skiff, Brian; Thirouin, Audrey; Trilling, David; Wasserman, Lawrence H.; Willman, Mark
Keywords: SAO
Abstract: Though pairs of dynamically associated asteroids in the Main Belt have been identified and studied for over a decade, very few pair systems have been identified in the near-Earth asteroid population. We present data and analysis that supports the existence of two genetically related pairs in near-Earth space. The members of the individual systems, 2015 EE7 - 2015 FP124 and 2017 SN16 - 2018 RY7, are found to be of the same spectral taxonomic class, and both pairs are interpreted to have volatile-poor compositions. In conjunction with dynamical arguments, this suggests that these two systems formed via YORP spin-up and/or dissociation of a binary precursor. Backwards orbital integrations suggest a separation age of <10 kyr for the pair 2017 SN16 - 2018 RY7, making these objects amongst the youngest multiple asteroid systems known to date. A unique separation age was not realized for 2015 EE7 - 2015 FP124 due to large uncertainties associated with these objects' orbits. Determining the ages of such young pairs is of great value for testing models of space weathering and asteroid spin-state evolution. As the NEO catalog continues to grow with current and future discovery surveys, it is expected that more NEO pairs will be found, thus providing an ideal laboratory for studying time dependent evolutionary processes that are relevant to asteroids throughout the Solar System.
LRG-BEASTS: Transmission Spectroscopy and Retrieval Analysis of the Highly Inflated Saturn-mass Planet WASP-39bKirk, JamesLópez-Morales, MercedesWheatley, Peter J.Weaver, Ian C.Skillen, IanLouden, TomMcCormac, JamesEspinoza, Néstor2019DOI: info:10.3847/1538-3881/ab397dThe Astronomical Journalv. 158 144 1440004-6256
Kirk, James, López-Morales, Mercedes, Wheatley, Peter J., Weaver, Ian C., Skillen, Ian, Louden, Tom, McCormac, James, and Espinoza, Néstor. 2019. "LRG-BEASTS: Transmission Spectroscopy and Retrieval Analysis of the Highly Inflated Saturn-mass Planet WASP-39b." The Astronomical Journal 158: 144. https://doi.org/10.3847/1538-3881/ab397d
ID: 154617
Type: article
Authors: Kirk, James; López-Morales, Mercedes; Wheatley, Peter J.; Weaver, Ian C.; Skillen, Ian; Louden, Tom; McCormac, James; Espinoza, Néstor
Keywords: SAO
Abstract: We present a ground-based transmission spectrum and comprehensive retrieval analysis of the highly inflated Saturn-mass planet WASP-39b. We obtained low-resolution spectra (R ≈ 400) of a transit of WASP-39b using the ACAM instrument on the 4.2 m William Herschel Telescope as part of the LRG-BEASTS survey. Our transmission spectrum is in good agreement with previous ground- and space-based observations of WASP- 39b, and covers a wavelength range of 4000-9000 Å. Previous analyses of this exoplanet have retrieved water abundances that span more than four orders of magnitude, which in turn lead to conclusions of a subsolar or highly supersolar atmospheric metallicity. In order to determine the cause of the large discrepancies in the literature regarding WASP-39b's atmospheric metallicity, we performed retrieval analyses of all literature data sets. Our retrievals, which assume equilibrium chemistry, recovered highly supersolar metallicities for all data sets. When running our retrievals on a combined spectrum, spanning 0.3-5 μm, we recovered an atmospheric metallicity of {282}-58+65× solar. We find that stellar activity has a negligible effect on the derived abundances and instead conclude that different assumptions made during retrieval analyses lead to the reported water abundances that differ by orders of magnitude. This in turn has significant consequences for the conclusions we draw. This is the fourth planet to be observed as part of the LRG-BEASTS survey, which is demonstrating that 4 m class telescopes can obtain low-resolution transmission spectra with precisions of around one atmospheric scale height.
Using X-Ray Morphological Parameters to Strengthen Galaxy Cluster Mass Estimates via Machine LearningGreen, Sheridan B.Ntampaka, MichelleNagai, DaisukeLovisari, LorenzoDolag, KlausEckert, DominiqueZuHone, John A.2019DOI: info:10.3847/1538-4357/ab426fThe Astrophysical Journalv. 884 33 330004-637X
Green, Sheridan B., Ntampaka, Michelle, Nagai, Daisuke, Lovisari, Lorenzo, Dolag, Klaus, Eckert, Dominique, and ZuHone, John A. 2019. "Using X-Ray Morphological Parameters to Strengthen Galaxy Cluster Mass Estimates via Machine Learning." The Astrophysical Journal 884: 33. https://doi.org/10.3847/1538-4357/ab426f
ID: 154618
Type: article
Authors: Green, Sheridan B.; Ntampaka, Michelle; Nagai, Daisuke; Lovisari, Lorenzo; Dolag, Klaus; Eckert, Dominique; ZuHone, John A.
Keywords: SAO
Abstract: We present a machine-learning approach for estimating galaxy cluster masses, trained using both Chandra and eROSITA mock X-ray observations of 2041 clusters from the Magneticum simulations. We train a random forest (RF) regressor, an ensemble learning method based on decision tree regression, to predict cluster masses using an input feature set. The feature set uses core-excised X-ray luminosity and a variety of morphological parameters, including surface brightness concentration, smoothness, asymmetry, power ratios, and ellipticity. The regressor is cross-validated and calibrated on a training sample of 1615 clusters (80% of sample), and then results are reported as applied to a test sample of 426 clusters (20% of sample). This procedure is performed for two different mock observation series in an effort to bracket the potential enhancement in mass predictions that can be made possible by including dynamical state information. The first series is computed from idealized Chandra-like mock cluster observations, with high spatial resolution, long exposure time (1 Ms), and the absence of background. The second series is computed from realistic-condition eROSITA mocks with lower spatial resolution, short exposures (2 ks), instrument effects, and background photons modeled. We report a 20% reduction in the mass estimation scatter when either series is used in our RF model compared to a standard regression model that only employs core-excised luminosity. The morphological parameters that hold the highest feature importance are smoothness, asymmetry, and surface brightness concentration. Hence these parameters, which encode the dynamical state of the cluster, can be used to make more accurate predictions of cluster masses in upcoming surveys, offering a crucial step forward for cosmological analyses.
The X-Ray Halo Scaling Relations of Supermassive Black HolesGaspari, M.Eckert, D.Ettori, S.Tozzi, P.Bassini, L.Rasia, E.Brighenti, F.Sun, M.Borgani, S.Johnson, S. D.Tremblay, Grant R.Stone, J. M.Temi, P.Yang, H. -Y K.Tombesi, F.Cappi, M.2019DOI: info:10.3847/1538-4357/ab3c5dThe Astrophysical Journalv. 884 169 1690004-637X
Gaspari, M., Eckert, D., Ettori, S., Tozzi, P., Bassini, L., Rasia, E., Brighenti, F., Sun, M., Borgani, S., Johnson, S. D., Tremblay, Grant R., Stone, J. M., Temi, P., Yang, H. -Y K., Tombesi, F., and Cappi, M. 2019. "The X-Ray Halo Scaling Relations of Supermassive Black Holes." The Astrophysical Journal 884: 169. https://doi.org/10.3847/1538-4357/ab3c5d
ID: 154619
Type: article
Authors: Gaspari, M.; Eckert, D.; Ettori, S.; Tozzi, P.; Bassini, L.; Rasia, E.; Brighenti, F.; Sun, M.; Borgani, S.; Johnson, S. D.; Tremblay, Grant R.; Stone, J. M.; Temi, P.; Yang, H. -Y K.; Tombesi, F.; Cappi, M.
Keywords: SAO
Abstract: We carry out a comprehensive Bayesian correlation analysis between hot halos and direct masses of supermassive black holes (SMBHs), by retrieving the X-ray plasma properties (temperature, luminosity, density, pressure, and masses) over galactic to cluster scales for 85 diverse systems. We find new key scalings, with the tightest relation being {M}\bullet -{\text{}}{T}{{x}}, followed by {M}\bullet -{\text{}}{L}{{x}}. The tighter scatter (down to 0.2 dex) and stronger correlation coefficient of all the X-ray halo scalings compared with the optical counterparts (as the {M}\bullet -{σ }{{e}}) suggest that plasma halos play a more central role than stars in tracing and growing SMBHs (especially those that are ultramassive). Moreover, {M}\bullet correlates better with the gas mass than dark matter mass. We show the important role of the environment, morphology, and relic galaxies/coronae, as well as the main departures from virialization /self-similarity via the optical/X-ray fundamental planes. We test the three major channels for SMBH growth: hot/Bondi-like models have inconsistent anticorrelation with X-ray halos and too low feeding; cosmological simulations find SMBH mergers as subdominant over most of cosmic time and too rare to induce a central-limit-theorem effect; the scalings are consistent with chaotic cold accretion, the rain of matter condensing out of the turbulent X-ray halos that sustains a long-term self-regulated feedback loop. The new correlations are major observational constraints for models of SMBH feeding/feedback in galaxies, groups, and clusters (e.g., to test cosmological hydrodynamical simulations), and enable the study of SMBHs not only through X-rays, but also via the Sunyaev-Zel'dovich effect (Compton parameter), lensing (total masses), and cosmology (gas fractions).
Supernova Photometric Classification Pipelines Trained on Spectroscopically Classified Supernovae from the Pan-STARRS1 Medium-deep SurveyVillar, Victoria AshleyBerger, EdoMiller, G.Chornock, R.Rest, A.Jones, D. O.Drout, M. R.Foley, R. J.Kirshner, RobertLunnan, R.Magnier, E.Milisavljevic, D.Sanders, N.Scolnic, D.2019DOI: info:10.3847/1538-4357/ab418cThe Astrophysical Journalv. 884 83 830004-637X
Villar, Victoria Ashley, Berger, Edo, Miller, G., Chornock, R., Rest, A., Jones, D. O., Drout, M. R., Foley, R. J., Kirshner, Robert, Lunnan, R., Magnier, E., Milisavljevic, D., Sanders, N., and Scolnic, D. 2019. "Supernova Photometric Classification Pipelines Trained on Spectroscopically Classified Supernovae from the Pan-STARRS1 Medium-deep Survey." The Astrophysical Journal 884: 83. https://doi.org/10.3847/1538-4357/ab418c
ID: 154620
Type: article
Authors: Villar, Victoria Ashley; Berger, Edo; Miller, G.; Chornock, R.; Rest, A.; Jones, D. O.; Drout, M. R.; Foley, R. J.; Kirshner, Robert; Lunnan, R.; Magnier, E.; Milisavljevic, D.; Sanders, N.; Scolnic, D.
Keywords: SAO
Abstract: Photometric classification of supernovae (SNe) is imperative as recent and upcoming optical time-domain surveys, such as the Large Synoptic Survey Telescope (LSST), overwhelm the available resources for spectrosopic follow-up. Here we develop a range of light curve (LC) classification pipelines, trained on 513 spectroscopically classified SNe from the Pan-STARRS1 Medium-Deep Survey (PS1-MDS): 357 Type Ia, 93 Type II, 25 Type IIn, 21 Type Ibc, and 17 Type I superluminous SNe (SLSNe). We present a new parametric analytical model that can accommodate a broad range of SN LC morphologies, including those with a plateau, and fit this model to data in four PS1 filters (g P1 r P1 i P1 z P1). We test a number of feature extraction methods, data augmentation strategies, and machine- learning algorithms to predict the class of each SN. Our best pipelines result in ≈90% average accuracy, ≈70% average purity, and ≈80% average completeness for all SN classes, with the highest success rates for SNe Ia and SLSNe and the lowest for SNe Ibc. Despite the greater complexity of our classification scheme, the purity of our SN Ia classification, ≈95%, is on par with methods developed specifically for Type Ia versus non-Type Ia binary classification. As the first of its kind, this study serves as a guide to developing and training classification algorithms for a wide range of SN types with a purely empirical training set, particularly one that is similar in its characteristics to the expected LSST main survey strategy. Future work will implement this classification pipeline on ≈3000 PS1/MDS LCs that lack spectroscopic classification.
Model-independent constraints on the hydrogen-ionizing emissivity at z > 6Mason, Charlotte A.Naidu, Rohan P.Tacchella, SandroLeja, Joel2019DOI: info:10.1093/mnras/stz2291Monthly Notices of the Royal Astronomical Societyv. 489 2669 26762669–26760035-8711
Mason, Charlotte A., Naidu, Rohan P., Tacchella, Sandro, and Leja, Joel. 2019. "Model-independent constraints on the hydrogen-ionizing emissivity at z > 6." Monthly Notices of the Royal Astronomical Society 489: 2669– 2676. https://doi.org/10.1093/mnras/stz2291
ID: 154621
Type: article
Authors: Mason, Charlotte A.; Naidu, Rohan P.; Tacchella, Sandro; Leja, Joel
Keywords: SAO
Abstract: Modelling reionization often requires significant assumptions about the properties of ionizing sources. Here, we infer the total output of hydrogen-ionizing photons (the ionizing emissivity, \dot{N}_\textrm {ion}) at z = 4-14 from current reionization constraints, being maximally agnostic to the properties of ionizing sources. We use a Bayesian analysis to fit for a non-parametric form of \dot{N}_\textrm {ion}, allowing us to flexibly explore the entire prior volume. We infer a declining \dot{N}_\textrm {ion} with redshift at z > 6, which can be used as a benchmark for reionization models. Model-independent reionization constraints from the cosmic microwave background (CMB) optical depth and Ly α and Ly β forest dark pixel fraction produce \dot{N}_\textrm {ion} evolution ( d\log _{10}\dot{\mathbf {N}}_{ion}/ dz|_{z=6\rArr 8} = -0.31± 0.35 dex) consistent with the declining UV luminosity density of galaxies, assuming constant ionizing photon escape fraction and efficiency. Including measurements from Ly α damping of galaxies and quasars produces a more rapid decline: d\log _{10}\dot{\mathbf {N}}_{ion}/ dz|_{z=6\rArr 8} =-0.44± 0.22 dex, steeper than the declining galaxy luminosity density (if extrapolated beyond M_UV≳ -13), and constrains the mid-point of reionization to z = 6.93 ± 0.14.
First Detection of Radio Linear Polarization in a Gamma-Ray Burst AfterglowUrata, YujiToma, KenjiHuang, KuiyunAsada, KeiichiNagai, HiroshiTakahashi, SatokoPetitpas, GlenTashiro, MakotoYamaoka, Kazutaka2019DOI: info:10.3847/2041-8213/ab48f3The Astrophysical Journalv. 884 L58 L580004-637X
Urata, Yuji, Toma, Kenji, Huang, Kuiyun, Asada, Keiichi, Nagai, Hiroshi, Takahashi, Satoko, Petitpas, Glen, Tashiro, Makoto, and Yamaoka, Kazutaka. 2019. "First Detection of Radio Linear Polarization in a Gamma-Ray Burst Afterglow." The Astrophysical Journal 884: L58. https://doi.org/10.3847/2041-8213/ab48f3
ID: 154622
Type: article
Authors: Urata, Yuji; Toma, Kenji; Huang, Kuiyun; Asada, Keiichi; Nagai, Hiroshi; Takahashi, Satoko; Petitpas, Glen; Tashiro, Makoto; Yamaoka, Kazutaka
Keywords: SAO
Abstract: We report the first detection of radio polarization of a gamma-ray burst (GRB) afterglow with the first intensive combined use of telescopes in the millimeter and submillimeter ranges for GRB 171205A. The linear polarization degree in the millimeter band at the subpercent level (0.27% ± 0.04%) is lower than those observed in late-time optical afterglows (weighted average of ̃1%). The Faraday depolarization by nonaccelerated, cool electrons in the shocked region is one of the possible mechanisms for the low value. This scenario requires a total energy that is larger by a factor of ̃10 than ordinary estimates without considering nonaccelerated electrons. The polarization position angle varies by at least 20° across the millimeter band, which is not inconsistent with this scenario. This result indicates that polarimetry in the millimeter and submillimeter ranges is a unique tool for investigating GRB energetics, and coincident observations with multiple frequencies or bands would provide more accurate measurements of the nonaccelerated electron fraction.
A Measurement of the Cosmic Microwave Background Lensing Potential and Power Spectrum from 500 deg2 of SPTpol Temperature and Polarization DataWu, W. L. K.Mocanu, L. M.Ade, P. A. R.Anderson, A. J.Austermann, J. E.Avva, J. S.Beall, J. A.Bender, A. N.Benson, B. A.Bianchini, F.Bleem, L. E.Carlstrom, J. E.Chang, C. L.Chiang, H. C.Citron, R.Corbett Moran, C.Crawford, T. M.Crites, A. T.de Haan, T.Dobbs, M. A.Everett, W.Gallicchio, J.George, E. M.Gilbert, A.Gupta, N.Halverson, N. W.Harrington, N.Henning, J. W.Hilton, G. C.Holder, G. P.Holzapfel, W. L.Hou, Z.Hrubes, J. D.Huang, N.Hubmayr, J.Irwin, K. D.Knox, L.Lee, A. T.Li, D.Lowitz, A.Manzotti, A.McMahon, J. J.Meyer, S. S.Millea, M.Montgomery, J.Nadolski, A.Natoli, T.Nibarger, J. P.Noble, G. I.Novosad, V.Omori, Y.Padin, S.Patil, S.Pryke, C.Reichardt, C. L.Ruhl, J. E.Saliwanchik, B. R.Sayre, J. T.Schaffer, K. K.Sievers, C.Simard, G.Smecher, G.Stark, Anthony A.Story, K. T.Tucker, C.Vanderlinde, K.Veach, T.Vieira, J. D.Wang, G.Whitehorn, N.Yefremenko, V.2019DOI: info:10.3847/1538-4357/ab4186The Astrophysical Journalv. 884 70 700004-637X
Wu, W. L. K., Mocanu, L. M., Ade, P. A. R., Anderson, A. J., Austermann, J. E., Avva, J. S., Beall, J. A., Bender, A. N., Benson, B. A., Bianchini, F., Bleem, L. E., Carlstrom, J. E., Chang, C. L., Chiang, H. C., Citron, R., Corbett Moran, C., Crawford, T. M., Crites, A. T., de Haan, T., Dobbs, M. A., Everett, W., Gallicchio, J., George, E. M., Gilbert, A., Gupta, N. et al. 2019. "A Measurement of the Cosmic Microwave Background Lensing Potential and Power Spectrum from 500 deg2 of SPTpol Temperature and Polarization Data." The Astrophysical Journal 884: 70. https://doi.org/10.3847/1538-4357/ab4186
ID: 154623
Type: article
Authors: Wu, W. L. K.; Mocanu, L. M.; Ade, P. A. R.; Anderson, A. J.; Austermann, J. E.; Avva, J. S.; Beall, J. A.; Bender, A. N.; Benson, B. A.; Bianchini, F.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Chiang, H. C.; Citron, R.; Corbett Moran, C.; Crawford, T. M.; Crites, A. T.; de Haan, T.; Dobbs, M. A.; Everett, W.; Gallicchio, J.; George, E. M.; Gilbert, A.; Gupta, N.; Halverson, N. W.; Harrington, N.; Henning, J. W.; Hilton, G. C.; Holder, G. P.; Holzapfel, W. L.; Hou, Z.; Hrubes, J. D.; Huang, N.; Hubmayr, J.; Irwin, K. D.; Knox, L.; Lee, A. T.; Li, D.; Lowitz, A.; Manzotti, A.; McMahon, J. J.; Meyer, S. S.; Millea, M.; Montgomery, J.; Nadolski, A.; Natoli, T.; Nibarger, J. P.; Noble, G. I.; Novosad, V.; Omori, Y.; Padin, S.; Patil, S.; Pryke, C.; Reichardt, C. L.; Ruhl, J. E.; Saliwanchik, B. R.; Sayre, J. T.; Schaffer, K. K.; Sievers, C.; Simard, G.; Smecher, G.; Stark, Anthony A.; Story, K. T.; Tucker, C.; Vanderlinde, K.; Veach, T.; Vieira, J. D.; Wang, G.; Whitehorn, N.; Yefremenko, V.
Keywords: SAO
Abstract: We present a measurement of the cosmic microwave background lensing potential using 500 deg2 of 150 GHz data from the SPTpol receiver on the South Pole Telescope. The lensing potential is reconstructed with signal-to-noise per mode greater than unity at lensing multipoles L ≲ 250, using a quadratic estimator on a combination of cosmic microwave background temperature and polarization maps. We report measurements of the lensing potential power spectrum in the multipole range of 100 of 150 GHz data from the SPTpol receiver on the South Pole Telescope. The lensing potential is reconstructed with signal-to-noise per mode greater than unity at lensing multipoles L ≲ 250, using a quadratic estimator on a combination of cosmic microwave background temperature and polarization maps. We report measurements of the lensing potential power spectrum in the multipole range of 100 of 150 GHz data from the SPTpol receiver on the South Pole Telescope. The lensing potential is reconstructed with signal-to-noise per mode greater than unity at lensing multipoles L ≲ 250, using a quadratic estimator on a combination of cosmic microwave background temperature and polarization maps. We report measurements of the lensing potential power spectrum in the multipole range of 100 MV}=0.944+/- 0.058({Stat}.)+/- 0.025 ({Sys}.); restricting to only polarization data, we find {A}POL}=0.906+/- 0.090 ({Stat}.)+/- 0.040 ({Sys}.). Considering statistical uncertainties alone, this is the most precise polarization-only lensing amplitude constraint to date (10.1σ) and is more precise than our temperature-only constraint. We perform null tests and consistency checks and find no evidence for significant contamination.
A Pluto-Charon Sonata. III. Growth of Charon from a Circum-Pluto Ring of DebrisKenyon, Scott J.Bromley, Benjamin C.2019DOI: info:10.3847/1538-3881/ab38b7The Astronomical Journalv. 158 142 1420004-6256
Kenyon, Scott J. and Bromley, Benjamin C. 2019. "A Pluto-Charon Sonata. III. Growth of Charon from a Circum-Pluto Ring of Debris." The Astronomical Journal 158: 142. https://doi.org/10.3847/1538-3881/ab38b7
ID: 154624
Type: article
Authors: Kenyon, Scott J.; Bromley, Benjamin C.
Keywords: SAO
Abstract: Current theory considers two options for the formation of the Pluto-Charon binary. In the hit-and-run model, a lower mass projectile barely hits the more massive Pluto, kicks up some debris, and remains bound to Pluto. In a graze-and-merge scenario, the projectile ejects substantial debris as it merges with Pluto. To investigate the graze-and-merge idea in more detail, we consider the growth of Charon-mass objects within a circum-Pluto ring of solids. Numerical calculations demonstrate that Charon analogs form rapidly within a swarm of planetesimals with initial radii r 0 ≈ 145-230 km. On timescales of ̃30-100 days, newly formed Charon analogs have semimajor axes, a ≈ 5-6 r P , and orbital eccentricities, e ≈ 0.1-0.3, similar to Charon analogs that remain bound after hit-and-run collisions with Pluto. Although the early growth of Charon analogs generates rings of small particles at a ≈ 50-275 r P , ejection of several 145-230 km leftovers by the central Pluto-Charon binary removes these small solids in 10-100 yr. Simple estimates suggest that small particles might survive the passage of 10-20 km objects ejected by the central binary. Our results indicate that the Pluto-Charon circumbinary satellite system was not formed by a graze-and-merge impact when the formation of Charon within a circum- Pluto disk leads to the ejection of several 100-200 km particles through the orbital plane of the Pluto-Charon binary. If a growing Charon ejects only much smaller particles, however, graze-and-merge impacts are a plausible formation channel for the Pluto-Charon binary and an ensemble of small, circumbinary satellites.
Prospects for TTV Detection and Dynamical Constraints with TESSHadden, SamBarclay, ThomasPayne, Matthew J.Holman, Matthew J.2019DOI: info:10.3847/1538-3881/ab384cThe Astronomical Journalv. 158 146 1460004-6256
Hadden, Sam, Barclay, Thomas, Payne, Matthew J., and Holman, Matthew J. 2019. "Prospects for TTV Detection and Dynamical Constraints with TESS." The Astronomical Journal 158: 146. https://doi.org/10.3847/1538-3881/ab384c
ID: 154625
Type: article
Authors: Hadden, Sam; Barclay, Thomas; Payne, Matthew J.; Holman, Matthew J.
Keywords: SAO
Abstract: We consider the potential for the Transiting Exoplanet Survey Satellite (TESS) to detect transit timing variations (TTVs) during both its nominal and extended mission phases. Building on previous estimates of the overall yield of planetary systems from the TESS mission, we predict that during its nominal two-year mission, TESS will observe measurable TTVs in ̃30 systems, from which { \mathcal O }(10) planet will get precise mass measurements from TTVs alone, ̃5 planets will have significant constraints placed on their masses from TTVs, and over a dozen systems will be singly transiting TTV systems. We consider a number of different extended mission scenarios, and predict that in a typical scenario, an extended mission will allow TESS to increase the number of systems with measurable TTVs to a total of ̃90, from which ̃15 planets will have precise mass measurements, another ̃15 will have significant constraints placed on their masses, and ̃60 will be singly transiting TTV systems. We also describe how follow-up transit observations of multiplanet systems discovered by the TESS mission can be optimally planned to maximize TTV mass and eccentricity constraints.
Solar Active Region Heating Diagnostics from High-temperature Emission Using the MaGIXSAthiray, P. S.Winebarger, Amy R.Barnes, Will T.Bradshaw, Stephen J.Savage, SabrinaWarren, Harry P.Kobayashi, KenChampey, PatrickGolub, LeonGlesener, Lindsay2019DOI: info:10.3847/1538-4357/ab3eb4The Astrophysical Journalv. 884 24 240004-637X
Athiray, P. S., Winebarger, Amy R., Barnes, Will T., Bradshaw, Stephen J., Savage, Sabrina, Warren, Harry P., Kobayashi, Ken, Champey, Patrick, Golub, Leon, and Glesener, Lindsay. 2019. "Solar Active Region Heating Diagnostics from High-temperature Emission Using the MaGIXS." The Astrophysical Journal 884: 24. https://doi.org/10.3847/1538-4357/ab3eb4
ID: 154626
Type: article
Authors: Athiray, P. S.; Winebarger, Amy R.; Barnes, Will T.; Bradshaw, Stephen J.; Savage, Sabrina; Warren, Harry P.; Kobayashi, Ken; Champey, Patrick; Golub, Leon; Glesener, Lindsay
Keywords: SAO
Abstract: The relative amount of high-temperature plasma has been found to be a useful diagnostic to determine the frequency of coronal heating on sub- resolution structures. When the loops are infrequently heated, a broad emission measure (EM) over a wider range of temperatures is expected. A narrower EM is expected for high-frequency heating where the loops are closer to equilibrium. The soft X-ray spectrum contains many spectral lines that provide high-temperature diagnostics, including lines from Fe XVII-XIX. This region of the solar spectrum will be observed by the Marshall Grazing Incidence Spectrometer (MaGIXS) in 2020. In this paper, we derive the expected spectral line intensity in MaGIXS to varying amounts of high-temperature plasma to demonstrate that a simple line ratio provides a powerful diagnostic to determine the heating frequency. Similarly, we examine ratios of AIA channel intensities, filter ratios from a XRT, and energy bands from the FOXSI sounding rocket to determine their sensitivity to this parameter. We find that both FOXSI and MaGIXS provide good diagnostic capabilities for high-temperature plasma. We then compare the predicted line ratios to the output of a numerical model and confirm that the MaGIXS ratios provide an excellent diagnostic for heating frequency.
The Soft X-Ray Counterpart of Hanny's Voorwerp Near IC 2497Fabbiano, GiuseppinaElvis, Martin2019DOI: info:10.3847/1538-4357/ab4187The Astrophysical Journalv. 884 163 1630004-637X
Fabbiano, Giuseppina and Elvis, Martin. 2019. "The Soft X-Ray Counterpart of Hanny's Voorwerp Near IC 2497." The Astrophysical Journal 884: 163. https://doi.org/10.3847/1538-4357/ab4187
ID: 154627
Type: article
Authors: Fabbiano, Giuseppina; Elvis, Martin
Keywords: SAO
Abstract: We report the detection in Chandra Advanced CCD Imaging Spectrometer archival data of an elongated soft (40 erg s-1. We infer an [O III]/soft-X-ray ratio in the range of ̃200, consistent with the highest values measured in some of the clouds of NGC 4151. Overall, given the uncertainties, Hanny's Voorwerp appears to be a feature consistent with the ionization cone emission of nearby AGNs. We estimate an X-ray recombination time of ̃2 × 107 yr, longer than the [O III] recombination time (̃8000 yr). This suggests that extended soft X-ray components may be a better diagnostic of overall long-term activity, while detection of an [O III] HV would point to a time-limited activity burst.
Coronal Response to Magnetically Suppressed CME Events in M-dwarf StarsAlvarado-Gómez, Julián D.Drake, Jeremy J.Moschou, Sofia P.Garraffo, CeciliaCohen, OferNASA LWS Focus Science Team: Solar-Stellar ConnectionYadav, Rakesh K.Fraschetti, Federico2019DOI: info:10.3847/2041-8213/ab44d0The Astrophysical Journalv. 884 L13 L130004-637X
Alvarado-Gómez, Julián D., Drake, Jeremy J., Moschou, Sofia P., Garraffo, Cecilia, Cohen, Ofer, NASA LWS Focus Science Team: Solar-Stellar Connection, Yadav, Rakesh K., and Fraschetti, Federico. 2019. "Coronal Response to Magnetically Suppressed CME Events in M-dwarf Stars." The Astrophysical Journal 884: L13. https://doi.org/10.3847/2041-8213/ab44d0
ID: 154628
Type: article
Authors: Alvarado-Gómez, Julián D.; Drake, Jeremy J.; Moschou, Sofia P.; Garraffo, Cecilia; Cohen, Ofer; NASA LWS Focus Science Team: Solar-Stellar Connection; Yadav, Rakesh K.; Fraschetti, Federico
Keywords: SAO
Abstract: We report the results of the first state-of-the-art numerical simulations of coronal mass ejections (CMEs) taking place in realistic magnetic field configurations of moderately active M-dwarf stars. Our analysis indicates that a clear, novel, and observable, coronal response is generated due to the collapse of the eruption and its eventual release into the stellar wind. Escaping CME events, weakly suppressed by the large-scale field, induce a flare-like signature in the emission from coronal material at different temperatures due to compression and associated heating. Such flare-like profiles display a distinctive temporal evolution in their Doppler shift signal (from red to blue), as the eruption first collapses toward the star and then perturbs the ambient magnetized plasma on its way outwards. For stellar fields providing partial confinement, CME fragmentation takes place, leading to rise and fall flow patterns which resemble the solar coronal rain cycle. In strongly suppressed events, the response is better described as a gradual brightening, in which the failed CME is deposited in the form of a coronal rain cloud leading to a much slower rise in the ambient high-energy flux by relatively small factors (̃2-3). In all the considered cases (escaping/confined) a fractional decrease in the emission from midrange coronal temperature plasma occurs, similar to the coronal dimming events observed on the Sun. Detection of the observational signatures of these CME-induced features requires a sensitive next generation X-ray space telescope.
ALMA resolves the hourglass magnetic field in G31.41+0.31Beltrán, M. T.Padovani, M.Girart, J. M.Galli, D.Cesaroni, R.Paladino, R.Anglada, G.Estalella, R.Osorio, M.Rao, R.Sánchez-Monge, Á.Zhang, Qizhou2019DOI: info:10.1051/0004-6361/201935701Astronomy and Astrophysicsv. 630 A54 A540004-6361
Beltrán, M. T., Padovani, M., Girart, J. M., Galli, D., Cesaroni, R., Paladino, R., Anglada, G., Estalella, R., Osorio, M., Rao, R., Sánchez-Monge, Á., and Zhang, Qizhou. 2019. "ALMA resolves the hourglass magnetic field in G31.41+0.31." Astronomy and Astrophysics 630: A54. https://doi.org/10.1051/0004-6361/201935701
ID: 154629
Type: article
Authors: Beltrán, M. T.; Padovani, M.; Girart, J. M.; Galli, D.; Cesaroni, R.; Paladino, R.; Anglada, G.; Estalella, R.; Osorio, M.; Rao, R.; Sánchez-Monge, Á.; Zhang, Qizhou
Keywords: SAO
Abstract: Context. Submillimeter Array (SMA) 870 μm polarization observations of the hot molecular core G31.41+0.31 revealed one of the clearest examples up to date of an hourglass-shaped magnetic field morphology in a high- mass star-forming region.
Aims: To better establish the role that the magnetic field plays in the collapse of G31.41+0.31, we carried out Atacama Large Millimeter/ submillimeter Array (ALMA) observations of the polarized dust continuum emission at 1.3 mm with an angular resolution four times higher than that of the previous (sub)millimeter observations to achieve an unprecedented image of the magnetic field morphology.
Methods: We used ALMA to perform full polarization observations at 233 GHz (Band 6). The resulting synthesized beam is 0''.28×0''.20 which, at the distance of the source, corresponds to a spatial resolution of 875 au.
Results: The observations resolve the structure of the magnetic field in G31.41+0.31 and allow us to study the field in detail. The polarized emission in the Main core of G31.41+0.41is successfully fit with a semi-analytical magnetostatic model of a toroid supported by magnetic fields. The best fit model suggests that the magnetic field is well represented by a poloidal field with a possible contribution of a toroidal component of 10% of the poloidal component, oriented southeast to northwest at approximately -44° and with an inclination of approximately -45°. The magnetic field is oriented perpendicular to the northeast to southwest velocity gradient detected in this core on scales from 103 to 104 au. This supports the hypothesis that the velocity gradient is due to rotation of the core and suggests that such a rotation has little effect on the magnetic field. The strength of the magnetic field estimated in the central region of the core with the Davis-Chandrasekhar-Fermi method is 8-13 mG and implies that the mass-to-flux ratio in this region is slightly supercritical.
Conclusions: The magnetic field in G31.41+0.31 maintains an hourglass-shaped morphology down to scales of <1000 au. Despite the magnetic field being important in G31.41+0.31, it is not enough to prevent fragmentation and collapse of the core, as demonstrated by the presence of at least four sources embedded in the center of the core.
The reduced images of the Stokes I, Q, and U (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz- bin/cat/J/A+A/630/A54
Optical characterization of WISE selected blazar candidatesde Menezes, RanierePeña-Herazo, Harold A.Marchesini, Ezequiel J.D'Abrusco, RaffaeleMasetti, NicolaNemmen, RodrigoMassaro, FrancescoRicci, FedericaLandoni, MarcoPaggi, AlessandroSmith, Howard A.2019DOI: info:10.1051/0004-6361/201936195Astronomy and Astrophysicsv. 630 A55 A550004-6361
de Menezes, Raniere, Peña-Herazo, Harold A., Marchesini, Ezequiel J., D'Abrusco, Raffaele, Masetti, Nicola, Nemmen, Rodrigo, Massaro, Francesco, Ricci, Federica, Landoni, Marco, Paggi, Alessandro, and Smith, Howard A. 2019. "Optical characterization of WISE selected blazar candidates." Astronomy and Astrophysics 630: A55. https://doi.org/10.1051/0004-6361/201936195
ID: 154630
Type: article
Authors: de Menezes, Raniere; Peña-Herazo, Harold A.; Marchesini, Ezequiel J.; D'Abrusco, Raffaele; Masetti, Nicola; Nemmen, Rodrigo; Massaro, Francesco; Ricci, Federica; Landoni, Marco; Paggi, Alessandro; Smith, Howard A.
Keywords: SAO
Abstract: Context. Over the last decade more than five thousand γ-ray sources have been detected by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope. Given the positional uncertainty of the telescope, nearly 30% of these sources remain without an obvious counterpart at lower energies. This has motivated the release of new catalogs of γ-ray counterpart candidates and several follow up campaigns in the last decade.
Aims: Recently, two new catalogs of blazar candidates were released. These are the improved and expanded version of the WISE Blazar-Like Radio-Loud Sources (WIBRaLS2) catalog and the Kernel Density Estimation selected candidate BL Lacs (KDEBLLACS) catalog, both selecting blazar-like sources based on their infrared colors from the Wide-field Infrared Survey Explorer (WISE). In this work we characterize these two catalogs, clarifying the true nature of their sources based on their optical spectra from SDSS data release 15, thus testing their efficiency in selecting true blazars.
Methods: We first selected all WIBRaLS2 and KDEBLLACS sources with available optical spectra in the footprint of Sloan Digital Sky Survey data release 15. We then analyzed these spectra to verify the nature of each selected candidate and to measure the fraction of the catalogs composed by spectroscopically confirmed blazars. Finally, we evaluated the impact of selection effects, especially those related to optical colors of WIBRaLS2/KDEBLLACS sources and their optical magnitude distributions.
Results: We found that at least ̃30% of each catalog is made up of confirmed blazars, with quasars being the major contaminants in the case of WIBRaLS2 (≈58%) and normal galaxies in the case of KDEBLLACS (≈38.2%). The spectral analysis also allowed us to identify the nature of 11 blazar candidates of uncertain type (BCUs) from the Fermi-LAT fourth Point Source Catalog (4FGL) and to find 25 new BL Lac objects.
Cloud G074.11+00.11: a stellar cluster in formationSaajasto, MikaHarju, JormaJuvela, MikaTie, LiuZhang, QizhouLiu, Sheng-YuanHirano, NaomiWu, YuefangKim, Kee-TaeTatematsu, Ken'ichiWang, KeThompson, Mark2019DOI: info:10.1051/0004-6361/201834991Astronomy and Astrophysicsv. 630 A69 A690004-6361
Saajasto, Mika, Harju, Jorma, Juvela, Mika, Tie, Liu, Zhang, Qizhou, Liu, Sheng-Yuan, Hirano, Naomi, Wu, Yuefang, Kim, Kee-Tae, Tatematsu, Ken'ichi, Wang, Ke, and Thompson, Mark. 2019. "Cloud G074.11+00.11: a stellar cluster in formation." Astronomy and Astrophysics 630: A69. https://doi.org/10.1051/0004-6361/201834991
ID: 154631
Type: article
Authors: Saajasto, Mika; Harju, Jorma; Juvela, Mika; Tie, Liu; Zhang, Qizhou; Liu, Sheng-Yuan; Hirano, Naomi; Wu, Yuefang; Kim, Kee-Tae; Tatematsu, Ken'ichi; Wang, Ke; Thompson, Mark
Keywords: SAO
Abstract: Context. We present molecular line and dust continuum observations of a Planck-detected cold cloud, G074.11+00.11. The cloud consists of a system of curved filaments and a central star-forming clump. The clump is associated with several infrared sources and H2O maser emission.
Aims: We aim to determine the mass distribution and gas dynamics within the clump to investigate if the filamentary structure seen around the clump repeats itself on a smaller scale, and to estimate the fractions of mass contained in dense cores and filaments. The velocity distribution of pristine dense gas can be used to investigate the global dynamical state of the clump, the role of filamentary inflows, filament fragmentation, and core accretion.
Methods: We used molecular line and continuum observations from single dish observatories and interferometric facilities to study the kinematics of the region.
Results: The molecular line observations show that the central clump may have formed as a result of a large-scale filament collision. The central clump contains three compact cores. Assuming a distance of 2.3 kpc, based on Gaia observations and a three-dimensional extinction method of background stars, the mass of the central clump exceeds 700 M, which is roughly 25% of the total mass of the cloud. Our virial analysis suggests that the central clump and all identified substructures are collapsing. We find no evidence for small- scale filaments associated with the cores.
Conclusions: Our observations indicate that the clump is fragmented into three cores with masses in the range [10, 50] M and that all three are collapsing. The presence of an H2O maser emission suggests active star formation. However, the CO lines show only weak signs of outflows. We suggest that the region is young and any processes leading to star formation have just recently begun.
The reduced radio datacubes and spectra are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz- bin/cat/J/A+A/630/A69Herschel is an ESA space observatory with science instruments provided by a European-led Principal Investigator consortia and with important participation from NASA.
A Parameter Space Exploration of Galaxy Cluster Mergers. II. Effects of Magnetic FieldsBrzycki, BryanZuhone, John2019DOI: info:10.3847/1538-4357/ab3983The Astrophysical Journalv. 883 118 1180004-637X
Brzycki, Bryan and Zuhone, John. 2019. "A Parameter Space Exploration of Galaxy Cluster Mergers. II. Effects of Magnetic Fields." The Astrophysical Journal 883: 118. https://doi.org/10.3847/1538-4357/ab3983
ID: 154632
Type: article
Authors: Brzycki, Bryan; Zuhone, John
Keywords: SAO
Abstract: The hot intracluster plasma in clusters of galaxies is weakly magnetized. Mergers between clusters produce gas compression and motions that can increase the magnetic field strength. In this work, we perform high-resolution nonradiative magnetohydrodynamics simulations of binary galaxy cluster mergers with magnetic fields, to examine the effects of these motions on the magnetic field configuration and strength, as well as the effect of the field on the gas itself. Our simulations sample a parameter space of initial mass ratios and impact parameters. During the first core passage of mergers, the magnetic energy increases via gas compression. After this, shear flows produce temporary, megaparsec- scale, strong-field "filament" structures. Lastly, magnetic fields grow stronger by turbulence. Field amplification is most effective for low- mass ratio mergers, but mergers with a large impact parameter can increase the magnetic energy more via shearing motions. The amplification of the magnetic field is most effective in between the first two core passages of each cluster merger. After the second core passage, the magnetic energy in this region gradually decreases. In general, the transfer of energy from gas motions to the magnetic field is not significant enough to have a substantial effect on gas mixing and the subsequent increase in entropy, which occurs in cluster cores as a result. In the absence of radiative cooling, this results in an overall decrease of the magnetic field strength in cluster cores. In these regions, the final magnetic field is isotropic, while it can be significantly tangential at larger radii.
COS Observations of the Cosmic Web: A Search for the Cooler Components of a Hot, X-Ray Identified FilamentConnor, ThomasZahedy, Fakhri S.Chen, Hsiao-WenCooper, Thomas J.Mulchaey, John S.Vikhlinin, Alexey2019DOI: info:10.3847/2041-8213/ab45f5The Astrophysical Journalv. 884 L20 L200004-637X
Connor, Thomas, Zahedy, Fakhri S., Chen, Hsiao-Wen, Cooper, Thomas J., Mulchaey, John S., and Vikhlinin, Alexey. 2019. "COS Observations of the Cosmic Web: A Search for the Cooler Components of a Hot, X-Ray Identified Filament." The Astrophysical Journal 884: L20. https://doi.org/10.3847/2041-8213/ab45f5
ID: 154633
Type: article
Authors: Connor, Thomas; Zahedy, Fakhri S.; Chen, Hsiao-Wen; Cooper, Thomas J.; Mulchaey, John S.; Vikhlinin, Alexey
Keywords: SAO
Abstract: In the local universe, a large fraction of the baryon content is believed to exist as diffuse gas in filaments. While this gas is directly observable in X-ray emission around clusters of galaxies, it is primarily studied through its UV absorption. Recently, X-ray observations of large-scale filaments connecting to the cosmic web around the nearby (z = 0.05584) cluster A133 were reported. One of these filaments is intersected by the sightline to quasar [VV98] J010250.2-220929, allowing for a first-ever census of cold, cool, and warm gas in a filament of the cosmic web where hot gas has been seen in X-ray emission. Here, we present UV observations with the Cosmic Origins Spectrograph and optical observations with the Magellan Echellette spectrograph of [VV98] J010250.2-220929. We find no evidence of cold, cool, or warm gas associated with the filament. In particular, we set a 2σ upper limit on Lyα absorption of log(N H I /cm-2) ) -1. As this sightline is ̃1100 pkpc (0.7R vir) from the center of A133, we suggest that all gas in the filament is hot at this location, or that any warm, cool, or cold components are small and clumpy. A broader census of this system-combining more UV sightlines, deeper X-ray observations, and a larger redshift catalog of cluster members-is needed to better understand the roles of filaments around clusters.
The X-ray properties of z > 6 quasars: no evident evolution of accretion physics in the first Gyr of the UniverseVito, F.Brandt, W. N.Bauer, F. E.Calura, F.Gilli, R.Luo, B.Shemmer, O.Vignali, C.Zamorani, G.Brusa, M.Civano, FrancescaComastri, A.Nanni, R.2019DOI: info:10.1051/0004-6361/201936217Astronomy and Astrophysicsv. 630 A118 A1180004-6361
Vito, F., Brandt, W. N., Bauer, F. E., Calura, F., Gilli, R., Luo, B., Shemmer, O., Vignali, C., Zamorani, G., Brusa, M., Civano, Francesca, Comastri, A., and Nanni, R. 2019. "The X-ray properties of z > 6 quasars: no evident evolution of accretion physics in the first Gyr of the Universe." Astronomy and Astrophysics 630: A118. https://doi.org/10.1051/0004-6361/201936217
ID: 154634
Type: article
Authors: Vito, F.; Brandt, W. N.; Bauer, F. E.; Calura, F.; Gilli, R.; Luo, B.; Shemmer, O.; Vignali, C.; Zamorani, G.; Brusa, M.; Civano, Francesca; Comastri, A.; Nanni, R.
Keywords: SAO
Abstract: Context. X-ray emission from quasars (QSOs) has been used to assess supermassive black hole accretion properties up to z ≈ 6. However, at z > 6 only ≈15 QSOs are covered by sensitive X-ray observations, preventing a statistically significant investigation of the X-ray properties of the QSO population in the first Gyr of the Universe.
Aims: We present new Chandra observations of a sample of 10 z > 6 QSOs, selected to have virial black-hole mass estimates from Mg II line spectroscopy (log {MBH}/{M_☉}=8.5-9.6) . Adding archival X-ray data for an additional 15 z > 6 QSOs, we investigate the X-ray properties of the QSO population in the first Gyr of the Universe. In particular, we focus on the LUV - LX relation, which is traced by the αox parameter, and the shape of their X-ray spectra.
Methods: We performed photometric analyses to derive estimates of the X-ray luminosities of our z > 6 QSOs, and thus their αox values and bolometric corrections (Kbol = Lbol/LX). We compared the resulting αox and Kbol distributions with the results found for QSO samples at lower redshift, and ran several statistical tests to check for a possible evolution of the LUV - LX relation. Finally, we performed a basic X-ray spectral analysis of the brightest z > 6 QSOs to derive their individual photon indices, and joint spectral analysis of the whole sample to estimate the average photon index.
Results: We detect seven of the new Chandra targets in at least one standard energy band, while two more are detected discarding energies E > 5 keV, where background dominates. We confirm a lack of significant evolution of αox with redshift, which extends the results from previous works up to z > 6 with a statistically significant QSO sample. Furthermore, we confirm the trend of an increasing bolometric correction with increasing luminosity found for QSOs at lower redshifts. The average power-law photon index of our sample (⟨Γ⟩ = 2.20-0.34+0.39 and ⟨Γ⟩ = 2.13-0.13+0.13 for sources with 30 net counts, respectively) is slightly steeper than, but still consistent with, typical QSOs at z = 1 - 6.
Conclusions: All of these results indicate a lack of substantial evolution of the inner accretion-disk and hot-corona structure in QSOs from low redshift to z > 6. Our data hint at generally high Eddington ratios at z > 6.
Potential of next-generation imaging spectrometers to detect and quantify methane point sources from spaceCusworth, Daniel H.Jacob, Daniel J.Varon, Daniel J.Chan Miller, ChristopherLiu, XiongChance, KellyThorpe, Andrew K.Duren, Riley M.Miller, Charles E.Thompson, David R.Frankenberg, ChristianGuanter, LuisRandles, Cynthia A.2019DOI: info:10.5194/amt-12-5655-2019Atmospheric Measurement Techniquesv. 12 5655 56685655–56681867-1381
Cusworth, Daniel H., Jacob, Daniel J., Varon, Daniel J., Chan Miller, Christopher, Liu, Xiong, Chance, Kelly, Thorpe, Andrew K., Duren, Riley M., Miller, Charles E., Thompson, David R., Frankenberg, Christian, Guanter, Luis, and Randles, Cynthia A. 2019. "Potential of next-generation imaging spectrometers to detect and quantify methane point sources from space." Atmospheric Measurement Techniques 12: 5655– 5668. https://doi.org/10.5194/amt-12-5655-2019
ID: 154635
Type: article
Authors: Cusworth, Daniel H.; Jacob, Daniel J.; Varon, Daniel J.; Chan Miller, Christopher; Liu, Xiong; Chance, Kelly; Thorpe, Andrew K.; Duren, Riley M.; Miller, Charles E.; Thompson, David R.; Frankenberg, Christian; Guanter, Luis; Randles, Cynthia A.
Keywords: SAO
Abstract: We examine the potential for global detection of methane plumes from individual point sources with the new generation of spaceborne imaging spectrometers (EnMAP, PRISMA, EMIT, SBG, CHIME) scheduled for launch in 2019-2025. These instruments are designed to map the Earth's surface at high spatial resolution (30 m×30 m) and have a spectral resolution of 7-10 nm in the 2200-2400 nm band that should also allow useful detection of atmospheric methane. We simulate scenes viewed by EnMAP (10 nm spectral resolution, 180 signal-to-noise ratio) using the EnMAP end-to- end simulation tool with superimposed methane plumes generated by large- eddy simulations. We retrieve atmospheric methane and surface reflectivity for these scenes using the IMAP-DOAS optimal estimation algorithm. We find an EnMAP precision of 3 %-7 % for atmospheric methane depending on surface type. This allows effective single-pass detection of methane point sources as small as 100 kg h-1 depending on surface brightness, surface homogeneity, and wind speed. Successful retrievals over very heterogeneous surfaces such as an urban mosaic require finer spectral resolution. We tested the EnMAP capability with actual plume observations over oil/gas fields in California from the Airborne Visible/Infrared Imaging Spectrometer - Next Generation (AVIRIS-NG) sensor (3 m×3 m pixel resolution, 5 nm spectral resolution, SNR 200-400), by spectrally and spatially downsampling the AVIRIS-NG data to match EnMAP instrument specifications. Results confirm that EnMAP can successfully detect point sources of ̃100 kg h-1 over bright surfaces. Source rates inferred with a generic integrated mass enhancement (IME) algorithm were lower for EnMAP than for AVIRIS- NG. Better agreement may be achieved with a more customized IME algorithm. Our results suggest that imaging spectrometers in space could play an important role in the future for quantifying methane emissions from point sources worldwide.
Radiative Association of Atomic and Ionic CarbonBabb, James F.Smyth, Ryan T.McLaughlin, Brendan M.2019DOI: info:10.3847/1538-4357/ab43cbThe Astrophysical Journalv. 884 155 1550004-637X
Babb, James F., Smyth, Ryan T., and McLaughlin, Brendan M. 2019. "Radiative Association of Atomic and Ionic Carbon." The Astrophysical Journal 884: 155. https://doi.org/10.3847/1538-4357/ab43cb
ID: 154636
Type: article
Authors: Babb, James F.; Smyth, Ryan T.; McLaughlin, Brendan M.
Keywords: SAO
Abstract: We present calculated cross sections and rate coefficients for the formation of the dicarbon cation ({{{C}}}2+) by the radiative association process in collisions of a {{C}}{(}3P) atom and a {{{C}}}+{(}2{P}o) ion. Molecular structure calculations for a number of low-lying doublet and quartet states of {{{C}}}2+ are used to obtain the potential energy surfaces and transition dipole moments coupling the states of interest, substantially increasing the available molecular data for {{{C}}}2+. Using a quantum-mechanical method, we explore a number of allowed transitions and determine those contributing to the radiative association process. The calculations extend the available data for this process down to the temperature of 100 K, where the rate coefficient is found to be about 2× {10}-18 {cm}}3 {{{s}}}-1. We provide analytical fits suitable for incorporation into astrochemical reaction databases.
The DSHARP Rings: Evidence of Ongoing Planetesimal Formation?Stammler, Sebastian M.Drążkowska, JoannaBirnstiel, TilKlahr, HubertDullemond, Cornelis P.Andrews, Sean M.2019DOI: info:10.3847/2041-8213/ab4423The Astrophysical Journalv. 884 L5 L50004-637X
Stammler, Sebastian M., Drążkowska, Joanna, Birnstiel, Til, Klahr, Hubert, Dullemond, Cornelis P., and Andrews, Sean M. 2019. "The DSHARP Rings: Evidence of Ongoing Planetesimal Formation?." The Astrophysical Journal 884: L5. https://doi.org/10.3847/2041-8213/ab4423
ID: 154637
Type: article
Authors: Stammler, Sebastian M.; Drążkowska, Joanna; Birnstiel, Til; Klahr, Hubert; Dullemond, Cornelis P.; Andrews, Sean M.
Keywords: SAO
Abstract: Recent high-resolution interferometric observations of protoplanetary disks at (sub)millimeter wavelengths reveal omnipresent substructures, such as rings, spirals, and asymmetries. A detailed investigation of eight rings detected in five disks by the DSHARP survey came to the conclusion that all rings are just marginally optically thick with optical depths between 0.2 and 0.5 at a wavelength of 1.25 mm. This surprising result could either be coincidental or indicate that the optical depth in all of the rings is regulated by the same process. We investigated if ongoing planetesimal formation could explain the "fine- tuned" optical depths in the DSHARP rings by removing dust and transforming it into "invisible" planetesimals. We performed a one- dimensional simulation of dust evolution in the second dust ring of the protoplanetary disk around HD 163296, including radial transport of gas and dust, dust growth and fragmentation, and planetesimal formation via gravitational collapse of sufficiently dense pebble concentrations. We show that planetesimal formation can naturally explain the observed optical depths if streaming instability regulates the midplane dust-to- gas ratio to unity. Furthermore, our simple monodisperse analytical model supports the hypothesis that planetesimal formation in dust rings should universally limit their optical depth to the observed range.
Spitzer Catalog of Herschel-selected Ultrared Dusty Star-forming GalaxiesMa, JingzheCooray, AsanthaNayyeri, HooshangBrown, AriannaGhotbi, NoahIvison, RobOteo, IvanDuivenvoorden, StevenGreenslade, JoshuaClements, DavidWardlow, JulieBattisti, Andrewda Cunha, ElisabeteAshby, Matthew L. N.Perez-Fournon, IsmaelRiechers, DominikOliver, SebEales, StephenNegrello, MattiaDye, SimonDunne, LorettaOmont, AlainScott, DouglasCox, PierreSerjeant, StephenMaddox, SteveValiante, Elisabetta2019DOI: info:10.3847/1538-4365/ab4194The Astrophysical Journal Supplement Seriesv. 244 30 300067-0049
Ma, Jingzhe, Cooray, Asantha, Nayyeri, Hooshang, Brown, Arianna, Ghotbi, Noah, Ivison, Rob, Oteo, Ivan, Duivenvoorden, Steven, Greenslade, Joshua, Clements, David, Wardlow, Julie, Battisti, Andrew, da Cunha, Elisabete, Ashby, Matthew L. N., Perez-Fournon, Ismael, Riechers, Dominik, Oliver, Seb, Eales, Stephen, Negrello, Mattia, Dye, Simon, Dunne, Loretta, Omont, Alain, Scott, Douglas, Cox, Pierre, Serjeant, Stephen et al. 2019. "Spitzer Catalog of Herschel-selected Ultrared Dusty Star-forming Galaxies." The Astrophysical Journal Supplement Series 244: 30. https://doi.org/10.3847/1538-4365/ab4194
ID: 154638
Type: article
Authors: Ma, Jingzhe; Cooray, Asantha; Nayyeri, Hooshang; Brown, Arianna; Ghotbi, Noah; Ivison, Rob; Oteo, Ivan; Duivenvoorden, Steven; Greenslade, Joshua; Clements, David; Wardlow, Julie; Battisti, Andrew; da Cunha, Elisabete; Ashby, Matthew L. N.; Perez-Fournon, Ismael; Riechers, Dominik; Oliver, Seb; Eales, Stephen; Negrello, Mattia; Dye, Simon; Dunne, Loretta; Omont, Alain; Scott, Douglas; Cox, Pierre; Serjeant, Stephen; Maddox, Steve; Valiante, Elisabetta
Keywords: SAO
Abstract: The largest Herschel extragalactic surveys, H-ATLAS and HerMES, have selected a sample of "ultrared" dusty star-forming galaxies (DSFGs) with rising SPIRE flux densities (S 500 > S 350 > S 250; the so-called "500 μm risers") as an efficient way for identifying DSFGs at higher redshift (z > 4). In this paper, we present a large Spitzer follow-up program of 300 Herschel ultrared DSFGs. We have obtained high-resolution Atacama Large Millimeter/submillimeter Array, Northern Extended Millimeter Array, and SMA data for 63 of them, which allow us to securely identify the Spitzer/IRAC counterparts and classify them as gravitationally lensed or unlensed. Within the 63 ultrared sources with high-resolution data, ̃65% appear to be unlensed and ̃27% are resolved into multiple components. We focus on analyzing the unlensed sample by directly performing multiwavelength spectral energy distribution modeling to derive their physical properties and compare with the more numerous z ̃ 2 DSFG population. The ultrared sample has a median redshift of 3.3, stellar mass of 3.7 × 1011 M , star formation rate (SFR) of 730 M yr-1, total dust luminosity of 9.0 × 1012 L , dust mass of 2.8 × 109 M , and V-band extinction of 4.0, which are all higher than those of the ALESS DSFGs. Based on the space density, SFR density, and stellar mass density estimates, we conclude that our ultrared sample cannot account for the majority of the star-forming progenitors of the massive, quiescent galaxies found in infrared surveys. Our sample contains the rarer, intrinsically most dusty, luminous, and massive galaxies in the early universe that will help us understand the physical drivers of extreme star formation.
From Scattered-light to Millimeter Emission: A Comprehensive View of the Gigayear-old System of HD 202628 and its Eccentric Debris RingFaramaz, VirginieKrist, JohnStapelfeldt, Karl R.Bryden, GeoffreyMamajek, Eric E.Matrà, LucaBooth, MarkFlaherty, KevinHales, Antonio S.Hughes, A. MeredithBayo, AmeliaCasassus, SimonCuadra, JorgeOlofsson, JohanSu, Kate Y. L.Wilner, David J.2019DOI: info:10.3847/1538-3881/ab3ec1The Astronomical Journalv. 158 162 1620004-6256
Faramaz, Virginie, Krist, John, Stapelfeldt, Karl R., Bryden, Geoffrey, Mamajek, Eric E., Matrà, Luca, Booth, Mark, Flaherty, Kevin, Hales, Antonio S., Hughes, A. Meredith, Bayo, Amelia, Casassus, Simon, Cuadra, Jorge, Olofsson, Johan, Su, Kate Y. L., and Wilner, David J. 2019. "From Scattered-light to Millimeter Emission: A Comprehensive View of the Gigayear-old System of HD 202628 and its Eccentric Debris Ring." The Astronomical Journal 158: 162. https://doi.org/10.3847/1538-3881/ab3ec1
ID: 154639
Type: article
Authors: Faramaz, Virginie; Krist, John; Stapelfeldt, Karl R.; Bryden, Geoffrey; Mamajek, Eric E.; Matrà, Luca; Booth, Mark; Flaherty, Kevin; Hales, Antonio S.; Hughes, A. Meredith; Bayo, Amelia; Casassus, Simon; Cuadra, Jorge; Olofsson, Johan; Su, Kate Y. L.; Wilner, David J.
Keywords: SAO
Abstract: We present here new observations of the eccentric debris ring surrounding the Gyr-old solar-type star HD 202628: at millimeter wavelengths with ALMA, at far-infrared wavelengths with Herschel, and in scattered light with the Hubble Space Telescope (HST). The ring inner edge is found to be consistent between ALMA and HST data. As radiation pressure affects small grains seen in scattered-light, the ring appears broader at optical than at millimeter wavelengths. The best fit to the ring seen with ALMA has inner and outer edges at 143.1 ± 1.7 au and 165.5 ± 1.4, respectively, and an inclination of 57.°4 ± 0.4 from face- on. The offset of the ring center of symmetry from the star allows us to quantify its eccentricity to be e={0.09}-0.01+0.02. This eccentric feature is also detected in low resolution Herschel/PACS observations, under the form of a pericenter-glow. Combining the infrared and millimeter photometry, we retrieve a disk grain size distribution index of ̃-3.4, and therefore exclude in situ formation of the inferred belt-shaping perturber, for which we provide new dynamical constraints. Finally, ALMA images show four point-like sources that exceed 100 μJy, one of them being just interior to the ring. Although the presence of a background object cannot be excluded, we cannot exclude either that this source is circumplanetary material surrounding the belt-shaper, in which case degeneracies between its mass and orbital parameters could be lifted, allowing us to fully characterize such a distant planet in this mass and age regime for the very first time.
An 11 Earth-mass, Long-period Sub-Neptune Orbiting a Sun-like StarMayo, Andrew W.Rajpaul, Vinesh M.Buchhave, Lars A.Dressing, Courtney D.Mortier, AnneliesZeng, LiFortenbach, Charles D.Aigrain, SuzanneBonomo, Aldo S.Collier Cameron, AndrewCharbonneau, DavidCoffinet, AdrienCosentino, RosarioDamasso, MarioDumusque, XavierMartinez Fiorenzano, A. F.Haywood, Raphaëlle D.Latham, David W.López-Morales, MercedesMalavolta, LucaMicela, GiusiMolinari, EmilioPearce, LoganPepe, FrancescoPhillips, DavidPiotto, GiampaoloPoretti, EnnioRice, KenSozzetti, AlessandroUdry, Stephane2019DOI: info:10.3847/1538-3881/ab3e2fThe Astronomical Journalv. 158 165 1650004-6256
Mayo, Andrew W., Rajpaul, Vinesh M., Buchhave, Lars A., Dressing, Courtney D., Mortier, Annelies, Zeng, Li, Fortenbach, Charles D., Aigrain, Suzanne, Bonomo, Aldo S., Collier Cameron, Andrew, Charbonneau, David, Coffinet, Adrien, Cosentino, Rosario, Damasso, Mario, Dumusque, Xavier, Martinez Fiorenzano, A. F., Haywood, Raphaëlle D., Latham, David W., López-Morales, Mercedes, Malavolta, Luca, Micela, Giusi, Molinari, Emilio, Pearce, Logan, Pepe, Francesco, Phillips, David et al. 2019. "An 11 Earth-mass, Long-period Sub-Neptune Orbiting a Sun-like Star." The Astronomical Journal 158: 165. https://doi.org/10.3847/1538-3881/ab3e2f
ID: 154640
Type: article
Authors: Mayo, Andrew W.; Rajpaul, Vinesh M.; Buchhave, Lars A.; Dressing, Courtney D.; Mortier, Annelies; Zeng, Li; Fortenbach, Charles D.; Aigrain, Suzanne; Bonomo, Aldo S.; Collier Cameron, Andrew; Charbonneau, David; Coffinet, Adrien; Cosentino, Rosario; Damasso, Mario; Dumusque, Xavier; Martinez Fiorenzano, A. F.; Haywood, Raphaëlle D.; Latham, David W.; López-Morales, Mercedes; Malavolta, Luca; Micela, Giusi; Molinari, Emilio; Pearce, Logan; Pepe, Francesco; Phillips, David; Piotto, Giampaolo; Poretti, Ennio; Rice, Ken; Sozzetti, Alessandro; Udry, Stephane
Keywords: SAO
Abstract: Although several thousands of exoplanets have now been detected and characterized, observational biases have led to a paucity of long- period, low-mass exoplanets with measured masses and a corresponding lag in our understanding of such planets. In this paper we report the mass estimation and characterization of the long-period exoplanet Kepler- 538b. This planet orbits a Sun-like star (V = 11.27) with {M}* ={0.892}-0.035+0.051 M and {R}* ={0.8717}-0.0061+0.0064 R . Kepler-538b is a {2.215}-0.034+0.040 R sub-Neptune with a period of P = 81.73778 ± 0.00013 days. It is the only known planet in the system. We collected radial velocity (RV) observations with the High Resolution Echelle Spectrometer (HIRES) on Keck I and High Accuracy Radial velocity Planet Searcher in North hemisphere (HARPS-N) on the Telescopio Nazionale Galileo (TNG). We characterized stellar activity by a Gaussian process with a quasi- periodic kernel applied to our RV and cross-correlation function FWHM observations. By simultaneously modeling Kepler photometry, RV, and FWHM observations, we found a semi-amplitude of K={1.68}-0.38+0.39 m s-1 and a planet mass of {M}p={10.6}-2.4+2.5 M . Kepler-538b is the smallest planet beyond P = 50 days with an RV mass measurement. The planet likely consists of a significant fraction of ices (dominated by water ice), in addition to rocks/metals, and a small amount of gas. Sophisticated modeling techniques such as those used in this paper, combined with future spectrographs with ultra high-precision and stability will be vital for yielding more mass measurements in this poorly understood exoplanet regime. This in turn will improve our understanding of the relationship between planet composition and insolation flux and how the rocky to gaseous transition depends on planetary equilibrium temperature.
Speckle Observations and Orbits of Multiple StarsTokovinin, AndreiEverett, Mark E.Horch, Elliott P.Torres, GuillermoLatham, David W.2019DOI: info:10.3847/1538-3881/ab4137The Astronomical Journalv. 158 167 1670004-6256
Tokovinin, Andrei, Everett, Mark E., Horch, Elliott P., Torres, Guillermo, and Latham, David W. 2019. "Speckle Observations and Orbits of Multiple Stars." The Astronomical Journal 158: 167. https://doi.org/10.3847/1538-3881/ab4137
ID: 154641
Type: article
Authors: Tokovinin, Andrei; Everett, Mark E.; Horch, Elliott P.; Torres, Guillermo; Latham, David W.
Keywords: SAO
Abstract: We report results of speckle-interferometric monitoring of visual hierarchical systems using the newly commissioned instrument NN-EXPLORE Exoplanet and Stellar Speckle Imager at the 3.5 m WIYN telescope. During one year, 390 measurements of 129 resolved subsystems were made, while some targets were unresolved. Using our astrometry and archival data, we computed 36 orbits (27 for the first time). Spectro-interferometric orbits of seven pairs are determined by combining positional measurements with radial velocities measured, mostly, with the Center for Astrophysics digital speedometers. For the hierarchical systems HIP 65026 (periods 49 and 1.23 yr) and HIP 85209 (periods 34 and 1.23 yr) we determined both the inner and the outer orbits using astrometry and radial velocities and measured the mutual orbit inclinations of 11.°3 ± 1.°0 and 12.°0 ± 3.°0, respectively. Four bright stars are resolved for the first time; two of those are triple systems. Several visual subsystems announced in the literature are shown to be spurious. We note that subsystems in compact hierarchies with outer separations less than 100 au tend to have less eccentric orbits compared to wider hierarchies.
The Recent Burstiness of Star Formation in Galaxies at z ̃ 4.5 from Hα MeasurementsFaisst, Andreas L.Capak, Peter L.Emami, NajmehTacchella, SandroLarson, Kirsten L.2019DOI: info:10.3847/1538-4357/ab425bThe Astrophysical Journalv. 884 133 1330004-637X
Faisst, Andreas L., Capak, Peter L., Emami, Najmeh, Tacchella, Sandro, and Larson, Kirsten L. 2019. "The Recent Burstiness of Star Formation in Galaxies at z ̃ 4.5 from Hα Measurements." The Astrophysical Journal 884: 133. https://doi.org/10.3847/1538-4357/ab425b
ID: 154642
Type: article
Authors: Faisst, Andreas L.; Capak, Peter L.; Emami, Najmeh; Tacchella, Sandro; Larson, Kirsten L.
Keywords: SAO
Abstract: The redshift range z = 4-6 marks a transition phase between primordial and mature galaxy formation in which galaxies considerably increase their stellar mass, metallicity, and dust content. The study of galaxies in this redshift range is therefore important to understanding early galaxy formation and the fate of galaxies at later times. Here, we investigate the burstiness of the recent star formation history (SFH) of 221z ̃ 4.5 main-sequence galaxies at {log}(M/{M})> 9.7 by comparing their ultra-violet (UV) continuum, Hα luminosity, and Hα equivalent-width (EW). The Hα properties are derived from the Spitzer [3.6 μm]-[4.5 μm] broadband color, thereby properly taking into account model and photometric uncertainties. We find a significant scatter between Hα- and UV-derived luminosities and star formation rates (SFRs). About half of the galaxies show a significant excess in Hα compared to expectations from a constant smooth SFH. We also find a tentative anticorrelation between Hα EW and stellar mass, ranging from 1000 Å at {log}(M/{M})))> 11. Consulting models suggests that most z ̃ 4.5 galaxies had a burst of star formation within the last 50 Myr, increasing their SFRs by a factor of >5. The most massive galaxies on the other hand might decrease their SFRs and may be transitioning to a quiescent stage by z = 4. We identify differential dust attenuation (f) between stars and nebular regions as the main contributor to the uncertainty. With local galaxies selected by increasing Hα EW (reaching values similar to high-z galaxies), we predict that f approaches unity at z > 4, consistent with the extrapolation of measurements out to z = 2.
Prospects for X-Ray and FUV Observations to Provide Insight into the 'Cepheid Mass Problem'Evans, Nancy RemageEngle, Scott2019DOI: info:10.3389/fspas.2019.00065Frontiers in Astronomy and Space Sciencesv. 6 65 652296-987X
Evans, Nancy Remage and Engle, Scott. 2019. "Prospects for X-Ray and FUV Observations to Provide Insight into the "Cepheid Mass Problem"." Frontiers in Astronomy and Space Sciences 6: 65. https://doi.org/10.3389/fspas.2019.00065
ID: 154643
Type: article
Authors: Evans, Nancy Remage; Engle, Scott
Keywords: SAO
Abstract: The classical Cepheid Leavitt Law (Period-Luminosity relation) has been known for 100 years, and used as in extragalactic distance determination for nearly as long. However, Cepheids still present us with surprises. Recent results about X-ray behavior is just one example. Around minimum radius the pulsation wave from the envelope creates a disruption in the photosphere and chromosphere. X-ray activity, on the other hand remains constant at a low level at this phase. Just after maximum radius, however, X-ray flux increases sharply (four fold in the case of δ Cep). We summarize here the observational program to explore parameters involved and theoretical investigations searching for a basic understanding of this upper atmosphere phenomena.
Achievements of Hinode in the first eleven yearsHinode Review TeamAl-Janabi, KhalidAntolin, PatrickBaker, DeborahBellot Rubio, Luis R.Bradley, LouisaBrooks, David H.Centeno, RebeccaCulhane, J. LeonardDel Zanna, GiulioDoschek, George A.Fletcher, LyndsayHara, HirohisaHarra, Louise K.Hillier, Andrew S.Imada, ShinsukeKlimchuk, James A.Mariska, John T.Pereira, Tiago M. D.Reeves, Katharine K.Sakao, TaroSakurai, TakashiShimizu, ToshifumiShimojo, MasumiShiota, DaikouSolanki, Sami K.Sterling, Alphonse C.Su, YingnaSuematsu, YoshinoriTarbell, Theodore D.Tiwari, Sanjiv K.Toriumi, ShinUgarte-Urra, IgnacioWarren, Harry P.Watanabe, TetsuyaYoung, Peter R.2019DOI: info:10.1093/pasj/psz084Publications of the Astronomical Society of Japanv. 71 R1 R10004-6264
Hinode Review Team, Al-Janabi, Khalid, Antolin, Patrick, Baker, Deborah, Bellot Rubio, Luis R., Bradley, Louisa, Brooks, David H., Centeno, Rebecca, Culhane, J. Leonard, Del Zanna, Giulio, Doschek, George A., Fletcher, Lyndsay, Hara, Hirohisa, Harra, Louise K., Hillier, Andrew S., Imada, Shinsuke, Klimchuk, James A., Mariska, John T., Pereira, Tiago M. D., Reeves, Katharine K., Sakao, Taro, Sakurai, Takashi, Shimizu, Toshifumi, Shimojo, Masumi, Shiota, Daikou et al. 2019. "Achievements of Hinode in the first eleven years." Publications of the Astronomical Society of Japan 71: R1. https://doi.org/10.1093/pasj/psz084
ID: 154644
Type: article
Authors: Hinode Review Team; Al-Janabi, Khalid; Antolin, Patrick; Baker, Deborah; Bellot Rubio, Luis R.; Bradley, Louisa; Brooks, David H.; Centeno, Rebecca; Culhane, J. Leonard; Del Zanna, Giulio; Doschek, George A.; Fletcher, Lyndsay; Hara, Hirohisa; Harra, Louise K.; Hillier, Andrew S.; Imada, Shinsuke; Klimchuk, James A.; Mariska, John T.; Pereira, Tiago M. D.; Reeves, Katharine K.; Sakao, Taro; Sakurai, Takashi; Shimizu, Toshifumi; Shimojo, Masumi; Shiota, Daikou; Solanki, Sami K.; Sterling, Alphonse C.; Su, Yingna; Suematsu, Yoshinori; Tarbell, Theodore D.; Tiwari, Sanjiv K.; Toriumi, Shin; Ugarte-Urra, Ignacio; Warren, Harry P.; Watanabe, Tetsuya; Young, Peter R.
Keywords: SAO
Abstract: Hinode is Japan's third solar mission following Hinotori (1981-1982) and Yohkoh (1991-2001): it was launched on 2006 September 22 and is in operation currently. Hinode carries three instruments: the Solar Optical Telescope, the X-Ray Telescope, and the EUV Imaging Spectrometer. These instruments were built under international collaboration with the National Aeronautics and Space Administration and the UK Science and Technology Facilities Council, and its operation has been contributed to by the European Space Agency and the Norwegian Space Center. After describing the satellite operations and giving a performance evaluation of the three instruments, reviews are presented on major scientific discoveries by Hinode in the first eleven years (one solar cycle long) of its operation. This review article concludes with future prospects for solar physics research based on the achievements of Hinode.
Hubble Frontier Field photometric catalogues of Abell 370 and RXC J2248.7-4431: multiwavelength photometry, photometric redshifts, and stellar propertiesBradač, MarušaHuang, Kuang-HanFontana, AdrianoCastellano, MarcoMerlin, EmilianoAmorín, RicardoHoag, AustinStrait, VictoriaSantini, PaolaRyan, Russell E.Casertano, StefanoLemaux, Brian C.Lubin, Lori M.Schmidt, Kasper B.Schrabback, TimTreu, Tommasovon der Linden, AnjaMason, Charlotte A.Wang, Xin2019DOI: info:10.1093/mnras/stz2119Monthly Notices of the Royal Astronomical Societyv. 489 99 10799–1070035-8711
Bradač, Maruša, Huang, Kuang-Han, Fontana, Adriano, Castellano, Marco, Merlin, Emiliano, Amorín, Ricardo, Hoag, Austin, Strait, Victoria, Santini, Paola, Ryan, Russell E., Casertano, Stefano, Lemaux, Brian C., Lubin, Lori M., Schmidt, Kasper B., Schrabback, Tim, Treu, Tommaso, von der Linden, Anja, Mason, Charlotte A., and Wang, Xin. 2019. "Hubble Frontier Field photometric catalogues of Abell 370 and RXC J2248.7-4431: multiwavelength photometry, photometric redshifts, and stellar properties." Monthly Notices of the Royal Astronomical Society 489: 99– 107. https://doi.org/10.1093/mnras/stz2119
ID: 154645
Type: article
Authors: Bradač, Maruša; Huang, Kuang-Han; Fontana, Adriano; Castellano, Marco; Merlin, Emiliano; Amorín, Ricardo; Hoag, Austin; Strait, Victoria; Santini, Paola; Ryan, Russell E.; Casertano, Stefano; Lemaux, Brian C.; Lubin, Lori M.; Schmidt, Kasper B.; Schrabback, Tim; Treu, Tommaso; von der Linden, Anja; Mason, Charlotte A.; Wang, Xin
Keywords: SAO
Abstract: This paper presents multiwavelength photometric catalogues of the last two Hubble Frontier Fields (HFFs), the massive galaxy clusters Abell 370 and RXC J2248.7-4431. The photometry ranges from imaging performed on the Hubble Space Telescope to ground-based Very Large Telescope and Spitzer/Infrared Array Camera, in collaboration with the ASTRODEEP team, and using the ASTRODEEP pipeline. While the main purpose of this paper is to release the catalogues, we also perform, as a proof of concept, a brief analysis of z > 6 objects selected using dropout method, as well as spectroscopically confirmed sources and multiple images in both clusters. While dropout methods yield a sample of high-z galaxies, the addition of longer wavelength data reveals that as expected the samples have substantial contamination at the ̃30-45 per cent level by dusty galaxies at lower redshifts. Furthermore, we show that spectroscopic redshifts are still required to unambiguously determine redshifts of multiply imaged systems. Finally, the now publicly available ASTRODEEP catalogues were combined for all HFFs and used to explore stellar properties of a large sample of 20 000 galaxies across a large photometric redshift range. The powerful magnification provided by the HFF clusters allows for an exploration of the properties of galaxies with intrinsic stellar masses as low as M* ≳ 107 M and intrinsic star formation rates ̃0.1-1 M yr-1 at z > 6.
X-Ray Spectra from Plasmas with High-energy Electrons: κ-distributions and e−─e− BremsstrahlungCui, XiaohongFoster, Adam R.Yuasa, TakayukiSmith, Randall K.2019DOI: info:10.3847/1538-4357/ab5304The Astrophysical Journalv. 887 182 1820004-637X
Cui, Xiaohong, Foster, Adam R., Yuasa, Takayuki, and Smith, Randall K. 2019. "X-Ray Spectra from Plasmas with High-energy Electrons: κ-distributions and e─e Bremsstrahlung." The Astrophysical Journal 887: 182. https://doi.org/10.3847/1538-4357/ab5304
ID: 154508
Type: article
Authors: Cui, Xiaohong; Foster, Adam R.; Yuasa, Takayuki; Smith, Randall K.
Keywords: SAO
Abstract: Shocks, turbulence, and winds all influence the electron velocity distribution in hot plasmas, exciting lower-energy electrons and generating a high-energy (typically power-law) tail. This effect, typically described as a κ distribution can affect both the line and continuum X-ray spectra emitted by the plasma. Hahn & Savin proposed a "Maxwellian decomposition" to generate the rate coefficients of κ distributions. Using their method and the AtomDB atomic database, we have developed a general model to calculate the emission from a plasma with a κ distribution. We compare our κ results for the charge state distribution and spectra of oxygen with those from KAPPA package with the ion data available within the CHIANTI atomic database. Sufficiently energetic electrons, created either in a κ distribution or merely a very hot Maxwellian plasma, can also emit via electron─electron (e─e) bremsstrahlung, a process not previously included in AtomDB. We have added this process to AtomDB and apply it to calculate the temperature gradients, as well as the total spectra from the post-shock regions of an accreting magnetic cataclysmic variable. We find the contribution of e─e bremsstrahlung to the total spectra exceeds 10% at KT ∼ 100 keV, with the total emissivity in the post-shock accretion stream differing by more than 10% at energies above 60 keV.
What is the physics behind the Larson mass-size relation?Ballesteros-Paredes, J.Román-Zúñiga, C.Salomé, Q.Zamora-Avilés, M.Jiménez-Donaire, Maria J.2019DOI: info:10.1093/mnras/stz2575Monthly Notices of the Royal Astronomical Societyv. 490 2648 26552648–26550035-8711
Ballesteros-Paredes, J., Román-Zúñiga, C., Salomé, Q., Zamora-Avilés, M., and Jiménez-Donaire, Maria J. 2019. "What is the physics behind the Larson mass-size relation?." Monthly Notices of the Royal Astronomical Society 490: 2648– 2655. https://doi.org/10.1093/mnras/stz2575
ID: 154509
Type: article
Authors: Ballesteros-Paredes, J.; Román-Zúñiga, C.; Salomé, Q.; Zamora-Avilés, M.; Jiménez-Donaire, Maria J.
Keywords: SAO
Abstract: Different studies have reported a power-law mass-size relation M ∝ Rq for ensembles of molecular clouds. In the case of nearby clouds, the index of the power-law q is close to 2. However, for clouds spread all over the Galaxy, indexes larger than 2 are reported. We show that indexes larger than 2 could be the result of line-of-sight superposition of emission that does not belong to the cloud itself. We found that a random factor of gas contamination, between 0.001 per cent and 10 per cent of the line of sight, allows to reproduce the mass-size relation with q ̃ 2.2-2.3 observed in Galactic CO surveys. Furthermore, for dense cores within a single cloud, or molecular clouds within a single galaxy, we argue that, even in these cases, there is observational and theoretical evidence that some degree of superposition may be occurring. However, additional effects may be present in each case, and are briefly discussed. We also argue that defining the fractal dimension of clouds via the mass-size relation is not adequate, since the mass is not necessarily a proxy to the area, and the size reported in M-R relations is typically obtained from the square root of the area, rather than from an estimation of the size independent from the area. Finally, we argue that the statistical analysis of finding clouds satisfying the Larson's relations does not mean that each individual cloud is in virial equilibrium.
Waldmeier Effect in Stellar CyclesGarg, SuyogKarak, Bidya BinayEgeland, RickySoon, WillieBaliunas, Sallie2019DOI: info:10.3847/1538-4357/ab4a17The Astrophysical Journalv. 886 132 1320004-637X
Garg, Suyog, Karak, Bidya Binay, Egeland, Ricky, Soon, Willie, and Baliunas, Sallie. 2019. "Waldmeier Effect in Stellar Cycles." The Astrophysical Journal 886: 132. https://doi.org/10.3847/1538-4357/ab4a17
ID: 154510
Type: article
Authors: Garg, Suyog; Karak, Bidya Binay; Egeland, Ricky; Soon, Willie; Baliunas, Sallie
Keywords: SAO
Abstract: One of the most robust features of the solar magnetic cycle is that the stronger cycles rise faster than the weaker ones. This is popularly known as the Waldmeier Effect, which has been known for more than 100 yr. This fundamental feature of the solar cycle has not only practical implications, e.g., in predicting the solar cycle, but also implications in understanding the solar dynamo. Here we ask whether the Waldmeier Effect exists in other Sun-like stars. To answer this question, we analyze the Ca II H and K S-index from Mount Wilson Observatory for 21 Sun-like G─K stars. We specifically check two aspects of Waldmeier Effect, namely, (1) WE1: the anticorrelation between the rise times and the peaks and (2) WE2: the positive correlation between rise rates and amplitudes. We show that, except for HD 16160, HD 81809, HD 155886, and HD 161239, all stars considered in the analysis show WE2, while WE1 is found to be present only in some of the stars studied. Furthermore, the WE1 correlation is weaker than the WE2. Both WE1 and WE2 exist in the solar S-index as well. Similar to the solar cycles, the magnetic cycles of many stars are asymmetric about their maxima. The existence of the Waldmeier Effect and asymmetric cycles in Sun-like stars suggests that the dynamo mechanism which operates in the Sun is also operating in other stars.
The Nature of the Broadband X-Ray Variability in the Dwarf Seyfert Galaxy NGC 4395Kammoun, E. S.Nardini, E.Zoghbi, A.Miller, J. M.Cackett, E. M.Gallo, E.Reynolds, M. T.Risaliti, G.Barret, D.Brandt, W. N.Brenneman, L. W.Kaastra, J. S.Koss, M.Lohfink, A. M.Mushotzky, R. F.Raymond, JohnStern, D.2019DOI: info:10.3847/1538-4357/ab5110The Astrophysical Journalv. 886 145 1450004-637X
Kammoun, E. S., Nardini, E., Zoghbi, A., Miller, J. M., Cackett, E. M., Gallo, E., Reynolds, M. T., Risaliti, G., Barret, D., Brandt, W. N., Brenneman, L. W., Kaastra, J. S., Koss, M., Lohfink, A. M., Mushotzky, R. F., Raymond, John, and Stern, D. 2019. "The Nature of the Broadband X-Ray Variability in the Dwarf Seyfert Galaxy NGC 4395." The Astrophysical Journal 886: 145. https://doi.org/10.3847/1538-4357/ab5110
ID: 154511
Type: article
Authors: Kammoun, E. S.; Nardini, E.; Zoghbi, A.; Miller, J. M.; Cackett, E. M.; Gallo, E.; Reynolds, M. T.; Risaliti, G.; Barret, D.; Brandt, W. N.; Brenneman, L. W.; Kaastra, J. S.; Koss, M.; Lohfink, A. M.; Mushotzky, R. F.; Raymond, John; Stern, D.
Keywords: SAO
Abstract: We present a flux-resolved X-ray analysis of the dwarf Seyfert 1.8 galaxy NGC 4395, based on three archival XMM-Newton and one archival NuSTAR observations. The source is known to harbor a low-mass black hole (∼ {10}4{--}{{a}} {few} × {10}5 {M}ȯ ) and shows strong variability in the full X-ray range during these observations. We model the flux-resolved spectra of the source assuming three absorbing layers: neutral, mildly ionized, and highly ionized ({N}{{H}}∼ 1.6× {10}22{--}3.4× {10}23 {cm}}-2, ∼ 0.8{--}7.8× {10}22 {cm}}-2, and 3.8 × 1022 cm−2, respectively). The source also shows intrinsic variability by a factor of ∼3 on short timescales, which is due to changes in the nuclear flux, assumed to be a power law (Γ = 1.6─1.67). Our results show a positive correlation between the intrinsic flux and the absorbers' ionization parameter. The covering fraction of the neutral absorber varies during the first XMM-Newton observation, which could explain the pronounced soft X-ray variability. However, the source remains fully covered by this layer during the other two observations, largely suppressing the soft X-ray variability. This suggests an inhomogeneous and layered structure in the broad-line region. We also find a difference in the characteristic timescale of the power spectra between different energy ranges and observations. We finally show simulated spectra with XRISM, eXTP, and Athena, which will allow us to characterize the different absorbers, study their dynamics, and will help us identify their locations and sizes.
A SCUBA-2 selected Herschel-SPIRE dropout and the nature of this populationGreenslade, J.Aguilar, E.Clements, D. L.Dannerbauer, H.Cheng, T.Petitpas, GlenYang, C.Messias, H.Oteo, I.Farrah, D.Michałowski, M. J.Pérez Fournon, I.Aretxaga, I.Yun, M. S.Eales, S.Dunne, L.Cooray, A.Andreani, P.Hughes, D. H.Velázquez, M.Sánchez-Argüelles, D.Ponthieu, N.2019DOI: info:10.1093/mnras/stz2850Monthly Notices of the Royal Astronomical Societyv. 490 5317 53345317–53340035-8711
Greenslade, J., Aguilar, E., Clements, D. L., Dannerbauer, H., Cheng, T., Petitpas, Glen, Yang, C., Messias, H., Oteo, I., Farrah, D., Michałowski, M. J., Pérez Fournon, I., Aretxaga, I., Yun, M. S., Eales, S., Dunne, L., Cooray, A., Andreani, P., Hughes, D. H., Velázquez, M., Sánchez-Argüelles, D., and Ponthieu, N. 2019. "A SCUBA-2 selected Herschel-SPIRE dropout and the nature of this population." Monthly Notices of the Royal Astronomical Society 490: 5317– 5334. https://doi.org/10.1093/mnras/stz2850
ID: 154512
Type: article
Authors: Greenslade, J.; Aguilar, E.; Clements, D. L.; Dannerbauer, H.; Cheng, T.; Petitpas, Glen; Yang, C.; Messias, H.; Oteo, I.; Farrah, D.; Michałowski, M. J.; Pérez Fournon, I.; Aretxaga, I.; Yun, M. S.; Eales, S.; Dunne, L.; Cooray, A.; Andreani, P.; Hughes, D. H.; Velázquez, M.; Sánchez-Argüelles, D.; Ponthieu, N.
Keywords: SAO
Abstract: Dusty star-forming galaxies (DSFGs) detected at z > 4 provide important examples of the first generations of massive galaxies. However, few examples with spectroscopic confirmation are currently known, with Hershel struggling to detect significant numbers of z > 6 DSFGs. NGP6_D1 is a bright 850 μm source (12.3 ± 2.5 mJy) with no counterparts at shorter wavelengths (a SPIRE dropout). Interferometric observations confirm it is a single source, with no evidence for any optical or NIR emission, or nearby likely foreground lensing sources. No >3σ detected lines are seen in both LMT Redshift Search Receiver and IRAM 30 m EMIR spectra of NGP6_D1 across 32 GHz of bandwidth despite reaching detection limits of ̃ 1 mJy/500 km s^{-1}, so the redshift remains unknown. Template fitting suggests that NGP6_D1 is most likely between z = 5.8 and 8.3. SED analysis finds that NGP6_D1 is a ULIRG, with a dust mass ̃108-109 M and a star-formation rate of ̃500 M yr-1. We place upper limits on the gas mass of NGP6_D1 of MH2 11 M, consistent with a gas-to-dust ratio of ̃100-1000. We discuss the nature of NGP6_D1 in the context of the broader sub-mm population, and find that comparable SPIRE dropouts account for ̃20 per cent of all SCUBA-2 detected sources, but with a similar flux density distribution to the general population.
Exploring Plasma Heating in the Current Sheet Region in a Three-dimensional Coronal Mass Ejection SimulationReeves, Katharine K.Török, TiborMikić, ZoranLinker, JonMurphy, Nicholas A.2019DOI: info:10.3847/1538-4357/ab4ce8The Astrophysical Journalv. 887 103 1030004-637X
Reeves, Katharine K., Török, Tibor, Mikić, Zoran, Linker, Jon, and Murphy, Nicholas A. 2019. "Exploring Plasma Heating in the Current Sheet Region in a Three-dimensional Coronal Mass Ejection Simulation." The Astrophysical Journal 887: 103. https://doi.org/10.3847/1538-4357/ab4ce8
ID: 154513
Type: article
Authors: Reeves, Katharine K.; Török, Tibor; Mikić, Zoran; Linker, Jon; Murphy, Nicholas A.
Keywords: SAO
Abstract: We simulate a coronal mass ejection using a three-dimensional magnetohydrodynamic code that includes coronal heating, thermal conduction, and radiative cooling in the energy equation. The magnetic flux distribution at 1 R s is produced by a localized subsurface dipole superimposed on a global dipole field, mimicking the presence of an active region within the global corona. Transverse electric fields are applied near the polarity inversion line to introduce a transverse magnetic field, followed by the imposition of a converging flow to form and destabilize a flux rope, producing an eruption. We examine the quantities responsible for plasma heating and cooling during the eruption, including thermal conduction, radiation, adiabatic effects, coronal heating, and ohmic heating. We find that ohmic heating is an important contributor to hot temperatures in the current sheet region early in the eruption, but in the late phase, adiabatic compression plays an important role in heating the plasma there. Thermal conduction also plays an important role in the transport of thermal energy away from the current sheet region throughout the reconnection process, producing a "thermal halo" and widening the region of high temperatures. We simulate emission from solar telescopes for this eruption and find that there is evidence for emission from heated plasma above the flare loops late in the eruption, when the adiabatic heating is the dominant heating term. These results provide an explanation for hot supra-arcade plasma sheets that are often observed in X-rays and extreme ultraviolet wavelengths during the decay phase of large flares.
Comparison of the Scaling Properties of EUV Intensity Fluctuations in Coronal Hole and Quiet-Sun RegionsCadavid, Ana CristinaMiralles, Mari PazRomich, Kristine2019DOI: info:10.3847/1538-4357/ab4d4eThe Astrophysical Journalv. 886 143 1430004-637X
Cadavid, Ana Cristina, Miralles, Mari Paz, and Romich, Kristine. 2019. "Comparison of the Scaling Properties of EUV Intensity Fluctuations in Coronal Hole and Quiet-Sun Regions." The Astrophysical Journal 886: 143. https://doi.org/10.3847/1538-4357/ab4d4e
ID: 154514
Type: article
Authors: Cadavid, Ana Cristina; Miralles, Mari Paz; Romich, Kristine
Keywords: SAO
Abstract: Using detrended fluctuation analysis and rescaled range analysis, we investigate the scaling properties of extreme ultraviolet (EUV) intensity fluctuations of low-latitude coronal holes (CHs) and neighboring quiet-Sun (QS) regions in signals obtained with the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly instrument. Contemporaneous line-of-sight SDO/Helioseismic and Magnetic Imager magnetic fields provide a context for the physical environment. We find that the intensity fluctuations in the time series of EUV images present at each spatial point a scaling symmetry over the range ∼20 minute to ∼1 hr. Thus we are able to calculate a generalized Hurst exponent and produce image maps, not of physical quantities like intensity or temperature, but of a single dynamical parameter that sums up the statistical nature of the intensity fluctuations at each pixel. In QS regions and in CHs with magnetic bipoles, the scaling exponent (1.0 &lt α ≤ 1.5) corresponds to anticorrelated turbulent-like processes. In CHs, and in QS regions primarily associated with (open) magnetic field of dominant polarity, the generalized exponent (0.5 < α < 1) corresponds to positively correlated (persistent) processes. We identify a tendency for α ∼ 1 near CH boundaries and in other regions in which open and closed magnetic fields are in proximity. This is a signature of an underlying 1/f type process that is characteristic for self-organized criticality and shot-noise models.
Resolving the Metallicity Distribution of the Stellar Halo with the H3 SurveyConroy, CharlieNaidu, Rohan P.Zaritsky, DennisBonaca, AnaCargile, PhillipJohnson, Benjamin D.Caldwell, Nelson2019DOI: info:10.3847/1538-4357/ab5710The Astrophysical Journalv. 887 237 2370004-637X
Conroy, Charlie, Naidu, Rohan P., Zaritsky, Dennis, Bonaca, Ana, Cargile, Phillip, Johnson, Benjamin D., and Caldwell, Nelson. 2019. "Resolving the Metallicity Distribution of the Stellar Halo with the H3 Survey." The Astrophysical Journal 887: 237. https://doi.org/10.3847/1538-4357/ab5710
ID: 154515
Type: article
Authors: Conroy, Charlie; Naidu, Rohan P.; Zaritsky, Dennis; Bonaca, Ana; Cargile, Phillip; Johnson, Benjamin D.; Caldwell, Nelson
Keywords: SAO
Abstract: The Galactic stellar halo is predicted to have formed at least partially from the tidal disruption of accreted dwarf galaxies. This assembly history should be detectable in the orbital and chemical properties of stars. The H3 Survey is obtaining spectra for 200,000 stars and, when combined with Gaia data, is providing detailed orbital and chemical properties of Galactic halo stars. Unlike previous surveys of the halo, the H3 target selection is based solely on magnitude and Gaia parallax the survey therefore provides a nearly unbiased view of the entire stellar halo at high latitudes. In this paper we present the distribution of stellar metallicities as a function of Galactocentric distance and orbital properties for a sample of 4232 kinematically selected halo giants to 100 kpc. The stellar halo is relatively metal- rich, =-1.2, and there is no discernible metallicity gradient over the range 6 =-1.2, and there is no discernible metallicity gradient over the range 6 gal gal gal > 30 kpc, respectively. The Sagittarius stream dominates the metallicity distribution at 20─40 kpc for stars on prograde orbits. The Gaia─Enceladus merger remnant dominates the metallicity distribution for radial orbits to ≈30 kpc. Metal-poor stars with [Fe/H] < −2 are a small population of the halo at all distances and orbital categories. We associate the "in situ" stellar halo with stars displaying thick disk chemistry on halo-like orbits; such stars are confined to | z| < 10 {kpc}. The majority of the stellar halo is resolved into discrete features in chemical─orbital space, suggesting that the bulk of the stellar halo formed from the accretion and tidal disruption of dwarf galaxies. The relatively high metallicity of the halo derived in this work is a consequence of the unbiased selection function of halo stars and, in combination with the recent upward revision of the total stellar halo mass, implies a Galactic halo metallicity that is typical for its mass.
Mass Assembly of Stellar Systems and Their Evolution with the SMA (MASSES)-Full Data ReleaseStephens, Ian W.Bourke, Tyler L.Dunham, Michael M.Myers, Philip C.Pokhrel, RiwajTobin, John J.Arce, Héctor G.Sadavoy, Sarah I.Vorobyov, Eduard I.Pineda, Jaime E.Offner, Stella S. R.Lee, Katherine I.Kristensen, Lars E.Jørgensen, Jes K.Gurwell, Mark A.Goodman, Alyssa A.2019DOI: info:10.3847/1538-4365/ab5181The Astrophysical Journal Supplement Seriesv. 245 21 210067-0049
Stephens, Ian W., Bourke, Tyler L., Dunham, Michael M., Myers, Philip C., Pokhrel, Riwaj, Tobin, John J., Arce, Héctor G., Sadavoy, Sarah I., Vorobyov, Eduard I., Pineda, Jaime E., Offner, Stella S. R., Lee, Katherine I., Kristensen, Lars E., Jørgensen, Jes K., Gurwell, Mark A., and Goodman, Alyssa A. 2019. "Mass Assembly of Stellar Systems and Their Evolution with the SMA (MASSES)-Full Data Release." The Astrophysical Journal Supplement Series 245: 21. https://doi.org/10.3847/1538-4365/ab5181
ID: 154516
Type: article
Authors: Stephens, Ian W.; Bourke, Tyler L.; Dunham, Michael M.; Myers, Philip C.; Pokhrel, Riwaj; Tobin, John J.; Arce, Héctor G.; Sadavoy, Sarah I.; Vorobyov, Eduard I.; Pineda, Jaime E.; Offner, Stella S. R.; Lee, Katherine I.; Kristensen, Lars E.; Jørgensen, Jes K.; Gurwell, Mark A.; Goodman, Alyssa A.
Keywords: SAO
Abstract: We present and release the full data set for the Mass Assembly of Stellar Systems and their Evolution with the SMA (MASSES) survey. This survey used the Submillimeter Array (SMA) to image the 74 known protostars within the Perseus molecular cloud. The SMA was used in two array configurations to capture outflows for scales >30″ (>9000 au) and to probe scales down to ∼1″ (∼300 au). The protostars were observed with the 1.3 mm and 850 μm receivers simultaneously to detect continuum at both wavelengths and molecular line emission from CO(2─1), 13CO(2─1), C18O(2─1), N2D+(3─2), CO(3─2), HCO+(4─3), and H13CO+(4─3). Some of the observations also used the SMA's recently upgraded correlator, SWARM, whose broader bandwidth allowed for several more spectral lines to be observed (e.g., SO, H2CO, DCO+, DCN, CS, CN). Of the main continuum and spectral tracers observed, 84% of the images and cubes had emission detected. The median C18O(2─1) line width is ∼1.0 km s−1, which is slightly higher than those measured with single-dish telescopes at scales of 3000─20,000 au. Of the 74 targets, six are suggested to be first hydrostatic core candidates, and we suggest that L1451-mm is the best candidate. We question a previous continuum detection toward L1448 IRS2E. In the SVS 13 system, SVS 13A certainly appears to be the most evolved source, while SVS 13C appears to be hotter and more evolved than SVS 13B. The MASSES survey is the largest publicly available interferometric continuum and spectral line protostellar survey to date, and is largely unbiased as it only targets protostars in Perseus. All visibility (uv) data and imaged data are publicly available at https://dataverse.harvard.edu/dataverse/full_MASSES/.
Dark Energy Survey year 1 results: the relationship between mass and light around cosmic voidsFang, Y.Hamaus, N.Jain, B.Pandey, S.Pollina, G.Sánchez, C.Kovács, A.Chang, C.Carretero, J.Castander, F. J.Choi, A.Crocce, M.DeRose, J.Fosalba, P.Gatti, M.Gaztañaga, E.Gruen, D.Hartley, W. G.Hoyle, B.MacCrann, N.Prat, J.Rau, M. M.Rykoff, E. S.Samuroff, S.Sheldon, E.Troxel, M. A.Vielzeuf, P.Zuntz, J.Annis, J.Avila, S.Bertin, E.Brooks, D.Burke, D. L.Carnero Rosell, A.Carrasco Kind, M.Cawthon, R.da Costa, L. N.De Vicente, J.Desai, S.Diehl, H. T.Dietrich, J. P.Doel, P.Everett, S.Evrard, A. E.Flaugher, B.Frieman, J.García-Bellido, J.Gerdes, D. W.Gruendl, R. A.Gutierrez, G.Hollowood, D. L.James, David J.Jarvis, M.Kuropatkin, N.Lahav, O.Maia, M. A. G.Marshall, J. L.Melchior, P.Menanteau, F.Miquel, R.Palmese, A.Plazas, A. A.Romer, A. K.Roodman, A.Sanchez, E.Serrano, S.Sevilla-Noarbe, I.Smith, M.Soares-Santos, M.Sobreira, F.Suchyta, E.Swanson, M. E. C.Tarle, G.Thomas, D.Vikram, V.Walker, A. R.Weller, J.DES Collaboration2019DOI: info:10.1093/mnras/stz2805Monthly Notices of the Royal Astronomical Societyv. 490 3573 35873573–35870035-8711
Fang, Y., Hamaus, N., Jain, B., Pandey, S., Pollina, G., Sánchez, C., Kovács, A., Chang, C., Carretero, J., Castander, F. J., Choi, A., Crocce, M., DeRose, J., Fosalba, P., Gatti, M., Gaztañaga, E., Gruen, D., Hartley, W. G., Hoyle, B., MacCrann, N., Prat, J., Rau, M. M., Rykoff, E. S., Samuroff, S., Sheldon, E. et al. 2019. "Dark Energy Survey year 1 results: the relationship between mass and light around cosmic voids." Monthly Notices of the Royal Astronomical Society 490: 3573– 3587. https://doi.org/10.1093/mnras/stz2805
ID: 154517
Type: article
Authors: Fang, Y.; Hamaus, N.; Jain, B.; Pandey, S.; Pollina, G.; Sánchez, C.; Kovács, A.; Chang, C.; Carretero, J.; Castander, F. J.; Choi, A.; Crocce, M.; DeRose, J.; Fosalba, P.; Gatti, M.; Gaztañaga, E.; Gruen, D.; Hartley, W. G.; Hoyle, B.; MacCrann, N.; Prat, J.; Rau, M. M.; Rykoff, E. S.; Samuroff, S.; Sheldon, E.; Troxel, M. A.; Vielzeuf, P.; Zuntz, J.; Annis, J.; Avila, S.; Bertin, E.; Brooks, D.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Cawthon, R.; da Costa, L. N.; De Vicente, J.; Desai, S.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Everett, S.; Evrard, A. E.; Flaugher, B.; Frieman, J.; García-Bellido, J.; Gerdes, D. W.; Gruendl, R. A.; Gutierrez, G.; Hollowood, D. L.; James, David J.; Jarvis, M.; Kuropatkin, N.; Lahav, O.; Maia, M. A. G.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Miquel, R.; Palmese, A.; Plazas, A. A.; Romer, A. K.; Roodman, A.; Sanchez, E.; Serrano, S.; Sevilla-Noarbe, I.; Smith, M.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Vikram, V.; Walker, A. R.; Weller, J.; DES Collaboration
Keywords: SAO
Abstract: What are the mass and galaxy profiles of cosmic voids? In this paper, we use two methods to extract voids in the Dark Energy Survey (DES) Year 1 redMaGiC galaxy sample to address this question. We use either 2D slices in projection, or the 3D distribution of galaxies based on photometric redshifts to identify voids. For the mass profile, we measure the tangential shear profiles of background galaxies to infer the excess surface mass density. The signal-to-noise ratio for our lensing measurement ranges between 10.7 and 14.0 for the two void samples. We infer their 3D density profiles by fitting models based on N-body simulations and find good agreement for void radii in the range 15-85 Mpc. Comparison with their galaxy profiles then allows us to test the relation between mass and light at the 10 per cent level, the most stringent test to date. We find very similar shapes for the two profiles, consistent with a linear relationship between mass and light both within and outside the void radius. We validate our analysis with the help of simulated mock catalogues and estimate the impact of photometric redshift uncertainties on the measurement. Our methodology can be used for cosmological applications, including tests of gravity with voids. This is especially promising when the lensing profiles are combined with spectroscopic measurements of void dynamics via redshift- space distortions.
Formation of Massive Protostellar Clusters-Observations of Massive 70 μm Dark Molecular CloudsLi, ShanghuoZhang, QizhouPillai, ThusharaStephens, Ian W.Wang, JunzhiLi, Fei2019DOI: info:10.3847/1538-4357/ab464eThe Astrophysical Journalv. 886 130 1300004-637X
Li, Shanghuo, Zhang, Qizhou, Pillai, Thushara, Stephens, Ian W., Wang, Junzhi, and Li, Fei. 2019. "Formation of Massive Protostellar Clusters-Observations of Massive 70 μm Dark Molecular Clouds." The Astrophysical Journal 886: 130. https://doi.org/10.3847/1538-4357/ab464e
ID: 154518
Type: article
Authors: Li, Shanghuo; Zhang, Qizhou; Pillai, Thushara; Stephens, Ian W.; Wang, Junzhi; Li, Fei
Keywords: SAO
Abstract: We present Submillimeter Array observations of seven massive molecular clumps that are dark in the far-infrared for wavelengths up to 70 μm. Our 1.3 mm continuum images reveal 44 dense cores, with gas masses ranging from 1.4 to 77.1 M . Twenty-nine dense cores have masses greater than 8 M and the other 15 dense cores have masses between 1.4 and 7.5 M . Assuming the core density follows a power law in radius ρ ∝ r −b , the index b is found to be between 0.6 and 2.1, with a mean value of 1.3. The virial analysis reveals that the dense cores are not in virial equilibrium. CO outflow emission was detected toward six out of seven molecular clumps and associated with 17 dense cores. For five of these cores, CO emissions appear to have line wings at velocities of greater than 30 km s−1 with respect to the source systemic velocity, which indicates that most of the clumps harbor protostars and thus are not quiescent in star formation. The estimated outflow timescale increases with core mass, which likely indicates that massive cores have longer accretion timescales than less massive ones. The fragmentation analysis shows that the masses of low-mass and massive cores are roughly consistent with thermal and turbulent Jeans masses, respectively.
Hi-C 2.1 Observations of Jetlet-like Events at Edges of Solar Magnetic Network LanesPanesar, Navdeep K.Sterling, Alphonse C.Moore, Ronald L.Winebarger, Amy R.Tiwari, Sanjiv K.Savage, Sabrina L.Golub, Leon E.Rachmeler, Laurel A.Kobayashi, KenBrooks, David H.Cirtain, Jonathan W.De Pontieu, BartMcKenzie, David E.Morton, Richard J.Peter, HardiTesta, PaolaWalsh, Robert W.Warren, Harry P.2019DOI: info:10.3847/2041-8213/ab594aThe Astrophysical Journalv. 887 L8 L80004-637X
Panesar, Navdeep K., Sterling, Alphonse C., Moore, Ronald L., Winebarger, Amy R., Tiwari, Sanjiv K., Savage, Sabrina L., Golub, Leon E., Rachmeler, Laurel A., Kobayashi, Ken, Brooks, David H., Cirtain, Jonathan W., De Pontieu, Bart, McKenzie, David E., Morton, Richard J., Peter, Hardi, Testa, Paola, Walsh, Robert W., and Warren, Harry P. 2019. "Hi-C 2.1 Observations of Jetlet-like Events at Edges of Solar Magnetic Network Lanes." The Astrophysical Journal 887: L8. https://doi.org/10.3847/2041-8213/ab594a
ID: 154519
Type: article
Authors: Panesar, Navdeep K.; Sterling, Alphonse C.; Moore, Ronald L.; Winebarger, Amy R.; Tiwari, Sanjiv K.; Savage, Sabrina L.; Golub, Leon E.; Rachmeler, Laurel A.; Kobayashi, Ken; Brooks, David H.; Cirtain, Jonathan W.; De Pontieu, Bart; McKenzie, David E.; Morton, Richard J.; Peter, Hardi; Testa, Paola; Walsh, Robert W.; Warren, Harry P.
Keywords: SAO
Abstract: We present high-resolution, high-cadence observations of six, fine-scale, on-disk jet-like events observed by the High-resolution Coronal Imager 2.1 (Hi-C 2.1) during its sounding-rocket flight. We combine the Hi-C 2.1 images with images from the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) and the Interface Region Imaging Spectrograph (IRIS), and investigate each event's magnetic setting with co-aligned line-of-sight magnetograms from the SDO/Helioseismic and Magnetic Imager (HMI). We find that (i) all six events are jetlet-like (having apparent properties of jetlets), (ii) all six are rooted at edges of magnetic network lanes, (iii) four of the jetlet-like events stem from sites of flux cancelation between majority- polarity network flux and merging minority-polarity flux, and (iv) four of the jetlet-like events show brightenings at their bases reminiscent of the base brightenings in coronal jets. The average spire length of the six jetlet-like events (9000 ± 3000 km) is three times shorter than that for IRIS jetlets (27,000 ± 8000 km). While not ruling out other generation mechanisms, the observations suggest that at least four of these events may be miniature versions of both larger-scale coronal jets that are driven by minifilament eruptions and still-larger-scale solar eruptions that are driven by filament eruptions. Therefore, we propose that our Hi-C events are driven by the eruption of a tiny sheared-field flux rope, and that the flux rope field is built and triggered to erupt by flux cancelation.
Origins of Molecular Clouds in Early-type GalaxiesBabyk, Iu V.McNamara, B. R.Tamhane, P. D.Nulsen, P. E. J.Russell, H. R.Edge, A. C.2019DOI: info:10.3847/1538-4357/ab54ceThe Astrophysical Journalv. 887 149 1490004-637X
Babyk, Iu V., McNamara, B. R., Tamhane, P. D., Nulsen, P. E. J., Russell, H. R., and Edge, A. C. 2019. "Origins of Molecular Clouds in Early-type Galaxies." The Astrophysical Journal 887: 149. https://doi.org/10.3847/1538-4357/ab54ce
ID: 154520
Type: article
Authors: Babyk, Iu V.; McNamara, B. R.; Tamhane, P. D.; Nulsen, P. E. J.; Russell, H. R.; Edge, A. C.
Keywords: SAO
Abstract: We analyze Chandra observations of the hot atmospheres of 40 early spiral and elliptical galaxies. Using new temperature, density, cooling time, and mass profiles, we explore relationships between their hot atmospheres and cold molecular gas. Molecular gas mass correlates with atmospheric gas mass and density over four decades from central galaxies in clusters to normal giant ellipticals and early spirals. The mass and density relations follow power laws: {M}mol}\propto {M}{{X}}1.4+/- 0.1 and {M}mol}\propto {n}{{e}}1.8+/- 0.3, respectively, at 10 kpc. The ratio of molecular gas to atmospheric gas within a 10 kpc radius lies between 3% and 10% for early-type galaxies and between 3% and 50% for central galaxies in clusters. Early-type galaxies have detectable levels of molecular gas when their atmospheric cooling times fall below ∼1 Gyr at a radius of 10 kpc. A similar trend is found in central cluster galaxies. We find no relationship between the ratio of the cooling time to free-fall time, t c/t ff, and the presence or absence of molecular clouds in early-type galaxies. The data are consistent with much of the molecular gas in early-type galaxies having condensed from their hot atmospheres.
MOBSTER - III. HD 62658: a magnetic Bp star in an eclipsing binary with a non-magnetic `identical twin'Shultz, M. E.Johnston, C.Labadie-Bartz, J.Petit, V.David-Uraz, A.Kochukhov, Ø.Wade, G. A.Pepper, J.Stassun, K. G.Rodriguez, Joseph E.Lund, M. B.James, David J.2019DOI: info:10.1093/mnras/stz2846Monthly Notices of the Royal Astronomical Societyv. 490 4154 41654154–41650035-8711
Shultz, M. E., Johnston, C., Labadie-Bartz, J., Petit, V., David-Uraz, A., Kochukhov, Ø., Wade, G. A., Pepper, J., Stassun, K. G., Rodriguez, Joseph E., Lund, M. B., and James, David J. 2019. "MOBSTER - III. HD 62658: a magnetic Bp star in an eclipsing binary with a non-magnetic `identical twin'." Monthly Notices of the Royal Astronomical Society 490: 4154– 4165. https://doi.org/10.1093/mnras/stz2846
ID: 154521
Type: article
Authors: Shultz, M. E.; Johnston, C.; Labadie-Bartz, J.; Petit, V.; David-Uraz, A.; Kochukhov, Ø.; Wade, G. A.; Pepper, J.; Stassun, K. G.; Rodriguez, Joseph E.; Lund, M. B.; James, David J.
Keywords: SAO
Abstract: HD 62658 (B9p V) is a little-studied chemically peculiar star. Light curves obtained by the Kilodegree Extremely Little Telescope (KELT) and Transiting Exoplanet Survey Satellite (TESS) show clear eclipses with a period of about 4.75 d, as well as out-of-eclipse brightness modulation with the same 4.75 d period, consistent with synchronized rotational modulation of surface chemical spots. High-resolution ESPaDOnS circular spectropolarimetry shows a clear Zeeman signature in the line profile of the primary; there is no indication of a magnetic field in the secondary. PHOEBE modelling of the light curve and radial velocities indicates that the two components have almost identical masses of about 3 M. The primary's longitudinal magnetic field . The primary's longitudinal magnetic field z> varies between about +100 and -250 G, suggesting a surface magnetic dipole strength Bd = 850 G. Bayesian analysis of the Stokes V profiles indicates Bd = 650 G for the primary and Bd < 110 G for the secondary. The primary's line profiles are highly variable, consistent with the hypothesis that the out-of-eclipse brightness modulation is a consequence of rotational modulation of that star's chemical spots. We also detect a residual signal in the light curve after removal of the orbital and rotational modulations, which might be pulsational in origin; this could be consistent with the weak line profile variability of the secondary. This system represents an excellent opportunity to examine the consequences of magnetic fields for stellar structure via comparison of two stars that are essentially identical with the exception that one is magnetic. The existence of such a system furthermore suggests that purely environmental explanations for the origin of fossil magnetic fields are incomplete.
Transit Signatures of Inhomogeneous Clouds on Hot Jupiters: Insights from Microphysical Cloud ModelingPowell, DianaLouden, TomKreidberg, LauraZhang, XiGao, PeterParmentier, Vivien2019DOI: info:10.3847/1538-4357/ab55d9The Astrophysical Journalv. 887 170 1700004-637X
Powell, Diana, Louden, Tom, Kreidberg, Laura, Zhang, Xi, Gao, Peter, and Parmentier, Vivien. 2019. "Transit Signatures of Inhomogeneous Clouds on Hot Jupiters: Insights from Microphysical Cloud Modeling." The Astrophysical Journal 887: 170. https://doi.org/10.3847/1538-4357/ab55d9
ID: 154522
Type: article
Authors: Powell, Diana; Louden, Tom; Kreidberg, Laura; Zhang, Xi; Gao, Peter; Parmentier, Vivien
Keywords: SAO
Abstract: We determine the observability in transmission of inhomogeneous cloud cover on the limbs of hot Jupiters through post-processing a general circulation model to include cloud distributions computed using a cloud microphysics model. We find that both the east and west limbs often form clouds, but that the different properties of these clouds enhance the limb-to-limb differences compared to the clear case. Using the James Webb Space Telescope, it should be possible to detect the presence of cloud inhomogeneities by comparing the shape of the transit light curve at multiple wavelengths because inhomogeneous clouds impart a characteristic, wavelength-dependent signature. This method is statistically robust even with limited wavelength coverage, uncertainty on limb-darkening coefficients, and imprecise transit times. We predict that the short-wavelength slope varies strongly with temperature. The hot limbs of the hottest planets form higher-altitude clouds composed of smaller particles, leading to a strong Rayleigh slope. The near-infrared spectral features of clouds are almost always detectable, even when no spectral slope is visible in the optical. In some of our models a spectral window between 5 and 9 μm can be used to probe through the clouds and detect chemical spectral features. Our cloud particle size distributions are not lognormal and differ from species to species. Using the area- or mass-weighted particle size significantly alters the relative strength of the cloud spectral features compared to using the predicted size distribution. Finally, the cloud content of a given planet is sensitive to a species' desorption energy and contact angle, two parameters that could be constrained experimentally in the future.
Probing Coronal Magnetic Fields with Sungrazing Comets: H I Lyα from Pickup IonsRaymond, John C.Giordano, S.2019DOI: info:10.3847/1538-4357/ab4e95The Astrophysical Journalv. 887 45 450004-637X
Raymond, John C. and Giordano, S. 2019. "Probing Coronal Magnetic Fields with Sungrazing Comets: H I Lyα from Pickup Ions." The Astrophysical Journal 887: 45. https://doi.org/10.3847/1538-4357/ab4e95
ID: 154523
Type: article
Authors: Raymond, John C.; Giordano, S.
Keywords: SAO
Abstract: Observations of sungrazing comets can be used to probe the solar corona, to study the composition of the comets, and to investigate the plasma processes that govern the interaction between the coronal plasma and cometary gas. UVCS observations of the intensities and line profiles of H I Lyα trace the density, temperature, and outflow speed of the corona. Analysis of H I Lyα observations of comet C/2002 S2 showed a surprising split in the comet's Lyα tail and an asymmetry of redshifted and blueshifted emission across the tail axis. It was suggested that the velocity structure might result from a population of neutrals produced by charge transfer between pickup ions and cometary neutrals. Here we present numerical simulations of the H I Lyα intensity and velocity centroid for sungrazing comets under the assumptions that the magnetic field and solar wind are radial. The models qualitatively reproduce the observations of Comet C/2002 S2 and potentially explain the split tail morphology that was seen in C/2002 S2 and also C/2001 C2. They also match the observed red- and blueshifts, though the solar wind velocity needed to explain the blueshift implies strong Doppler dimming and requires a higher outgassing rate to match the light curve. However, the models do not match the observations in detail, and we discuss the remaining discrepancies and the uncertainties in the model. We briefly discuss the implications for other UVCS comet observations and sungrazing comet observations with the Metis coronagraph.
The High-Resolution Coronal Imager, Flight 2.1Rachmeler, Laurel A.Winebarger, Amy R.Savage, Sabrina L.Golub, LeonKobayashi, KenVigil, Genevieve D.Brooks, David H.Cirtain, Jonathan W.De Pontieu, BartMcKenzie, David E.Morton, Richard J.Peter, HardiTesta, PaolaTiwari, Sanjiv K.Walsh, Robert W.Warren, Harry P.Alexander, CarolineAnsell, DarrenBeabout, Brent L.Beabout, Dyana L.Bethge, Christian W.Champey, Patrick R.Cheimets, Peter N.Cooper, Mark A.Creel, Helen K.Gates, RichardGomez, CarlosGuillory, AnthonyHaight, HarlanHogue, William D.Holloway, ToddHyde, David W.Kenyon, RichardMarshall, Joseph N.McCracken, Jeff E.McCracken, KennethMitchell, Karen O.Ordway, MarkOwen, TimRanganathan, JaganRobertson, Bryan A.Payne, M. JaniePodgorski, WilliamPryor, JonathanSamra, JennaSloan, Mark D.Soohoo, Howard A.Steele, D. BrandonThompson, Furman V.Thornton, Gary S.Watkinson, BenjaminWindt, David2019DOI: info:10.1007/s11207-019-1551-2Solar Physicsv. 294 174 1740038-0938
Rachmeler, Laurel A., Winebarger, Amy R., Savage, Sabrina L., Golub, Leon, Kobayashi, Ken, Vigil, Genevieve D., Brooks, David H., Cirtain, Jonathan W., De Pontieu, Bart, McKenzie, David E., Morton, Richard J., Peter, Hardi, Testa, Paola, Tiwari, Sanjiv K., Walsh, Robert W., Warren, Harry P., Alexander, Caroline, Ansell, Darren, Beabout, Brent L., Beabout, Dyana L., Bethge, Christian W., Champey, Patrick R., Cheimets, Peter N., Cooper, Mark A., Creel, Helen K. et al. 2019. "The High-Resolution Coronal Imager, Flight 2.1." Solar Physics 294: 174. https://doi.org/10.1007/s11207-019-1551-2
ID: 154524
Type: article
Authors: Rachmeler, Laurel A.; Winebarger, Amy R.; Savage, Sabrina L.; Golub, Leon; Kobayashi, Ken; Vigil, Genevieve D.; Brooks, David H.; Cirtain, Jonathan W.; De Pontieu, Bart; McKenzie, David E.; Morton, Richard J.; Peter, Hardi; Testa, Paola; Tiwari, Sanjiv K.; Walsh, Robert W.; Warren, Harry P.; Alexander, Caroline; Ansell, Darren; Beabout, Brent L.; Beabout, Dyana L.; Bethge, Christian W.; Champey, Patrick R.; Cheimets, Peter N.; Cooper, Mark A.; Creel, Helen K.; Gates, Richard; Gomez, Carlos; Guillory, Anthony; Haight, Harlan; Hogue, William D.; Holloway, Todd; Hyde, David W.; Kenyon, Richard; Marshall, Joseph N.; McCracken, Jeff E.; McCracken, Kenneth; Mitchell, Karen O.; Ordway, Mark; Owen, Tim; Ranganathan, Jagan; Robertson, Bryan A.; Payne, M. Janie; Podgorski, William; Pryor, Jonathan; Samra, Jenna; Sloan, Mark D.; Soohoo, Howard A.; Steele, D. Brandon; Thompson, Furman V.; Thornton, Gary S.; Watkinson, Benjamin; Windt, David
Keywords: SAO
Abstract: The third flight of the High-Resolution Coronal Imager (Hi-C 2.1) occurred on May 29, 2018; the Sounding Rocket was launched from White Sands Missile Range in New Mexico. The instrument has been modified from its original configuration (Hi-C 1) to observe the solar corona in a passband that peaks near 172 Å, and uses a new, custom-built low-noise camera. The instrument targeted Active Region 12712, and captured 78 images at a cadence of 4.4 s (18:56:22 - 19:01:57 UT; 5 min and 35 s observing time). The image spatial resolution varies due to quasi- periodic motion blur from the rocket; sharp images contain resolved features of at least 0.47 arcsec. There are coordinated observations from multiple ground- and space-based telescopes providing an unprecedented opportunity to observe the mass and energy coupling between the chromosphere and the corona. Details of the instrument and the data set are presented in this paper.
The Interaction between the Supernova Remnant W41 and the Filamentary Infrared Dark Cloud G23.33-0.30Hogge, Taylor G.Jackson, James M.Allingham, DavidGuzman, Andres E.Killerby-Smith, NicholasKraemer, Kathleen E.Sanhueza, PatricioStephens, Ian W.Whitaker, J. Scott2019DOI: info:10.3847/1538-4357/ab5180The Astrophysical Journalv. 887 79 790004-637X
Hogge, Taylor G., Jackson, James M., Allingham, David, Guzman, Andres E., Killerby-Smith, Nicholas, Kraemer, Kathleen E., Sanhueza, Patricio, Stephens, Ian W., and Whitaker, J. Scott. 2019. "The Interaction between the Supernova Remnant W41 and the Filamentary Infrared Dark Cloud G23.33-0.30." The Astrophysical Journal 887: 79. https://doi.org/10.3847/1538-4357/ab5180
ID: 154525
Type: article
Authors: Hogge, Taylor G.; Jackson, James M.; Allingham, David; Guzman, Andres E.; Killerby-Smith, Nicholas; Kraemer, Kathleen E.; Sanhueza, Patricio; Stephens, Ian W.; Whitaker, J. Scott
Keywords: SAO
Abstract: G23.33-0.30 is a 600 M infrared dark molecular filament that exhibits large NH3 velocity dispersions (σ ∼ 8 km s−1) and bright, narrow NH3(3, 3) line emission. We have probed G23.33-0.30 at the (3, 3) line emission. We have probed G23.33-0.30 at the 3(3, 3) line is emitted by four rare NH3(3, 3) masers, which are excited by a large-scale shock impacting the filament. G23.33-0.30 also displays a velocity gradient along its length, a velocity discontinuity across its width, shock- tracing SiO(5─4) emission extended throughout the filament, and broad turbulent line widths in NH3(1, 1) through (6, 6), CS(5─4), and SiO(5─4), as well as an increased NH3 rotational temperature (T rot) and velocity dispersion (σ) associated with the shocked, blueshifted component. The correlations among T rot, σ, and V LSR imply that the shock is accelerating, heating, and adding turbulent energy to the filament gas. Given G23.33-0.30's location within the giant molecular cloud G23.0-0.4, we speculate that the shock and NH3(3, 3) masers originated from the supernova remnant (SNR) W41, which exhibits additional evidence of an interaction with G23.0-0.4. We have also detected the 1.3 mm dust continuum emission from at least three embedded molecular cores associated with G23.33-0.30. Although the cores have moderate gas masses (M = 7─10 M ), their large virial parameters (α = 4─9) suggest that they will not collapse to form stars. The turbulent line widths of the (α > 1) cores may indicate negative feedback due to the SNR shock.
The Broadband X-Ray Spectrum of the X-Ray-obscured Type 1 AGN 2MASX J193013.80+341049.5Kamraj, NikitaBaloković, MislavBrightman, MurrayStern, DanielHarrison, Fiona A.Assef, Roberto J.Koss, Michael J.Oh, KyuseokWalton, Dominic J.2019DOI: info:10.3847/1538-4357/ab57fcThe Astrophysical Journalv. 887 255 2550004-637X
Kamraj, Nikita, Baloković, Mislav, Brightman, Murray, Stern, Daniel, Harrison, Fiona A., Assef, Roberto J., Koss, Michael J., Oh, Kyuseok, and Walton, Dominic J. 2019. "The Broadband X-Ray Spectrum of the X-Ray-obscured Type 1 AGN 2MASX J193013.80+341049.5." The Astrophysical Journal 887: 255. https://doi.org/10.3847/1538-4357/ab57fc
ID: 154526
Type: article
Authors: Kamraj, Nikita; Baloković, Mislav; Brightman, Murray; Stern, Daniel; Harrison, Fiona A.; Assef, Roberto J.; Koss, Michael J.; Oh, Kyuseok; Walton, Dominic J.
Keywords: SAO
Abstract: We present results from modeling the broadband X-ray spectrum of the Type 1 active galactic nucleus (AGN) 2MASX J193013.80+341049.5 using NuSTAR, Swift, and archival XMM-Newton observations. We find this source to be highly X-ray obscured, with column densities exceeding 1023 cm−2 across all epochs of X-ray observations, spanning an 8 yr period. However, the source exhibits prominent broad optical emission lines, consistent with an unobscured Type 1 AGN classification. We fit the X-ray spectra with both phenomenological reflection models and physically motivated torus models to model the X-ray absorption. We examine the spectral energy distribution of this source and investigate some possible scenarios to explain the mismatch between X-ray and optical classifications. We compare the ratio of reddening to X-ray absorbing column density ({E}B-V/{N}{{H}}) and find that 2MASX J193013.80+341049.5 likely has a much lower dust-to-gas ratio relative to the Galactic interstellar medium, suggesting that the broad line region itself could provide the source of extra X-ray obscuration, being composed of low-ionization, dust-free gas.
The High-redshift Clusters Occupied by Bent Radio AGN (COBRA) Survey: Follow-up Optical ImagingGolden-Marx, EmmetBlanton, E. L.Paterno-Mahler, R.Brodwin, M.Ashby, Matthew L. N.Lemaux, B. C.Lubin, L. M.Gal, R. R.Tomczak, A. R.2019DOI: info:10.3847/1538-4357/ab5106The Astrophysical Journalv. 887 50 500004-637X
Golden-Marx, Emmet, Blanton, E. L., Paterno-Mahler, R., Brodwin, M., Ashby, Matthew L. N., Lemaux, B. C., Lubin, L. M., Gal, R. R., and Tomczak, A. R. 2019. "The High-redshift Clusters Occupied by Bent Radio AGN (COBRA) Survey: Follow-up Optical Imaging." The Astrophysical Journal 887: 50. https://doi.org/10.3847/1538-4357/ab5106
ID: 154527
Type: article
Authors: Golden-Marx, Emmet; Blanton, E. L.; Paterno-Mahler, R.; Brodwin, M.; Ashby, Matthew L. N.; Lemaux, B. C.; Lubin, L. M.; Gal, R. R.; Tomczak, A. R.
Keywords: SAO
Abstract: Here we present new red sequence overdensity measurements for 77 fields in the high-z Clusters Occupied by Bent Radio AGN (COBRA) survey, based on r- and i-band imaging taken with the Lowell Observatory's Discovery Channel Telescope. We observe 38 COBRA fields in the r-band and 90 COBRA fields in the i-band. By combining the r- and i-band photometry with our 3.6 and 4.5 μm Spitzer IRAC observations, we identify 39 red sequence cluster candidates that host a strong overdensity of galaxies when measuring the excess of red sequence galaxies relative to a background field. We initially treat the radio host as the cluster center and then determine a new cluster center based on the surface density of red sequence sources. Using our color selection, we identify which COBRA cluster candidates have strong red sequence populations. By removing foreground and background contaminants, we more securely determine which fields include cluster candidates with a higher significance than our single-band observations. Additionally, of the 77 fields we analyze with a redshift estimate, 26 include newly estimated photometric redshifts.
Local photoionization feedback effects on galaxiesObreja, AuraMacciò, Andrea V.Moster, BenjaminUdrescu, Silviu M.Buck, TobiasKannan, RahulDutton, Aaron A.Blank, Marvin2019DOI: info:10.1093/mnras/stz2639Monthly Notices of the Royal Astronomical Societyv. 490 1518 15381518–15380035-8711
Obreja, Aura, Macciò, Andrea V., Moster, Benjamin, Udrescu, Silviu M., Buck, Tobias, Kannan, Rahul, Dutton, Aaron A., and Blank, Marvin. 2019. "Local photoionization feedback effects on galaxies." Monthly Notices of the Royal Astronomical Society 490: 1518– 1538. https://doi.org/10.1093/mnras/stz2639
ID: 154528
Type: article
Authors: Obreja, Aura; Macciò, Andrea V.; Moster, Benjamin; Udrescu, Silviu M.; Buck, Tobias; Kannan, Rahul; Dutton, Aaron A.; Blank, Marvin
Keywords: SAO
Abstract: We implement an optically thin approximation for the effects of the local radiation field from stars and hot gas on the gas heating and cooling in the N-body smoothed particle hydrodynamics code GASOLINE2. We resimulate three galaxies from the NIHAO project: one dwarf, one Milky Way-like, and one massive spiral, and study what are the local radiation field effects on various galaxy properties. We also study the effects of varying the ultraviolet background (UVB) model, by running the same galaxies with two different UVBs. Galaxy properties at z = 0 like stellar mass, stellar effective mass radius, H I mass, and radial extent of the H I disc show significant changes between the models with and without the local radiation field, and smaller differences between the two UVB models. The intrinsic effect of the local radiation field through cosmic time is to increase the equilibrium temperature at the interface between the galaxies and their circumgalactic media (CGM), moving this boundary inwards, while leaving relatively unchanged the gas inflow rate. Consequently, the temperature of the inflow increases when considering the local radiation sources. This temperature increase is a function of total galaxy mass, with a median CGM temperature difference of one order of magnitude for the massive spiral. The local radiation field suppresses the stellar mass growth by 20 per cent by z = 0 for all three galaxies, while the H I mass is roughly halved. The differences in the gas phase diagrams, significantly impact the H I column densities, shifting their peaks in the distributions towards lower NH I.
New deep coronal spectra from the 2017 total solar eclipseKoutchmy, S.Baudin, F.Abdi, ShGolub, LeonSèvre, F.2019DOI: info:10.1051/0004-6361/201935681Astronomy and Astrophysicsv. 632 A86 A860004-6361
Koutchmy, S., Baudin, F., Abdi, Sh, Golub, Leon, and Sèvre, F. 2019. "New deep coronal spectra from the 2017 total solar eclipse." Astronomy and Astrophysics 632: A86. https://doi.org/10.1051/0004-6361/201935681
ID: 154529
Type: article
Authors: Koutchmy, S.; Baudin, F.; Abdi, Sh; Golub, Leon; Sèvre, F.
Keywords: SAO
Abstract: Context. The origin of the high temperature of the solar corona, in both the inner bright parts and the more outer parts showing flows toward the solar wind, is not understood well yet. Total eclipses permit a deep analysis of both the inner and the outer parts of the corona using the continuum white-light (W-L) radiations from electrons (K-corona), the superposed spectrum of forbidden emission lines from ions (E-corona), and the dust component with F-lines (F-corona). Aims: By sufficiently dispersing the W-L spectrum, the Fraunhofer (F) spectrum of the dust component of the corona appears and the continuum Thomson radiation can be evaluated. The superposed emission lines of ions with different degrees of ionization are studied to allow the measurement of temperatures, non-thermal velocities, Doppler shifts, and abundances to constrain the proposed heating mechanisms and understand the origin of flows that lead to solar wind. Methods: We describe a slit spectroscopic experiment of high spectral resolution to provide an analysis of the most typical parts of the quasi-minimum type corona observed during the total solar eclipse of Aug. 21, 2017 from Idaho, USA. Streamers, active region enhancements, and polar coronal holes (CHs) are measured well using deep spectra. Results: Sixty spectra are obtained during the totality with a long slit, covering ±3 solar radii in the range of 510 nm to 590 nm. The K+F continuum corona is exposed well up to two solar radii. The F-corona can be measured even at the solar limb. New weak emission lines were discovered or confirmed. The rarely observed Ar X line is detected almost everywhere; the Fe XIV and Ni XIII lines are clearly detected everywhere. For the first time hot lines are also measured inside the CH regions. The radial variations of the non-thermal turbulent velocities of the lines do not show a great departure from the average values. No significantly large Doppler shifts are seen anywhere in the inner or the middle corona. The wings of the Fe XIV line show some non-Gaussianity. Conclusions: Deep slit coronal spectra offered an opportunity for diagnosing several aspects of coronal physics during a well observed total eclipse without extended investments. The analysis of the ionic emission line profiles offers several powerful diagnostics of the coronal dynamics; the precise measurement of the F-continuum component provides insight into the ubiquitous dust corona at the solar limb.
Imprints of temperature fluctuations on the z ̃ 5 Lyman-α forest: a view from radiation-hydrodynamic simulations of reionizationWu, XiaohanMcQuinn, MatthewKannan, RahulD'Aloisio, AnsonBird, SimeonMarinacci, FedericoDavé, RomeelHernquist, Lars2019DOI: info:10.1093/mnras/stz2807Monthly Notices of the Royal Astronomical Societyv. 490 3177 31953177–31950035-8711
Wu, Xiaohan, McQuinn, Matthew, Kannan, Rahul, D'Aloisio, Anson, Bird, Simeon, Marinacci, Federico, Davé, Romeel, and Hernquist, Lars. 2019. "Imprints of temperature fluctuations on the z ̃ 5 Lyman-α forest: a view from radiation-hydrodynamic simulations of reionization." Monthly Notices of the Royal Astronomical Society 490: 3177– 3195. https://doi.org/10.1093/mnras/stz2807
ID: 154530
Type: article
Authors: Wu, Xiaohan; McQuinn, Matthew; Kannan, Rahul; D'Aloisio, Anson; Bird, Simeon; Marinacci, Federico; Davé, Romeel; Hernquist, Lars
Keywords: SAO
Abstract: Reionization leads to large spatial fluctuations in the intergalactic temperature that can persist well after its completion. We study the imprints of such fluctuations on the z ̃ 5 Ly α forest flux power spectrum using a set of radiation-hydrodynamic simulations that model different reionization scenarios. We find that large-scale coherent temperature fluctuations bring {̃}20-60{{ per cent}} extra power at k ̃ 0.002 s km-1, with the largest enhancements in the models where reionization is extended or ends the latest. On smaller scales (k ≳ 0.1 s km-1), we find that temperature fluctuations suppress power by {≲}10{{ per cent}}. We find that the shape of the power spectrum is mostly sensitive to the reionization mid-point rather than temperature fluctuations from reionization's patchiness. However, for all of our models with reionization mid-points of z ≤ 8 (z ≤ 12), the shape differences are {≲}20{{ per cent}} ({≲}40{{ per cent}}) because of a surprisingly well-matched cancellation between thermal broadening and pressure smoothing that occurs for realistic thermal histories. We also consider fluctuations in the ultraviolet background, finding their impact on the power spectrum to be much smaller than temperature fluctuations at k ≳ 0.01 s km-1. Furthermore, we compare our models to power spectrum measurements, finding that none of our models with reionization mid-points of z < 8 is strongly preferred over another and that all of our models with mid-points of z ≥ 8 are excluded at 2.5σ. Future measurements may be able to distinguish between viable reionization models if they can be performed at lower k or, alternatively, if the error bars on the high-k power can be reduced by a factor of 1.5.
A Comprehensive Chandra Study of the Disk Wind in the Black Hole Candidate 4U 1630-472Trueba, N.Miller, J. M.Kaastra, J.Zoghbi, A.Fabian, A. C.Kallman, T.Proga, D.Raymond, John2019DOI: info:10.3847/1538-4357/ab4f70The Astrophysical Journalv. 886 104 1040004-637X
Trueba, N., Miller, J. M., Kaastra, J., Zoghbi, A., Fabian, A. C., Kallman, T., Proga, D., and Raymond, John. 2019. "A Comprehensive Chandra Study of the Disk Wind in the Black Hole Candidate 4U 1630-472." The Astrophysical Journal 886: 104. https://doi.org/10.3847/1538-4357/ab4f70
ID: 154531
Type: article
Authors: Trueba, N.; Miller, J. M.; Kaastra, J.; Zoghbi, A.; Fabian, A. C.; Kallman, T.; Proga, D.; Raymond, John
Keywords: SAO
Abstract: The mechanisms that drive disk winds are a window into the physical processes that underlie the disk. Stellar-mass black holes are an ideal setting in which to explore these mechanisms, in part because their outbursts span a broad range in mass accretion rate. We performed a spectral analysis of the disk wind found in six Chandra/HETG observations of the black hole candidate 4U 1630−472, covering a range of luminosities over two distinct spectral states. We modeled both wind absorption and extended wind re-emission components using PION, a self- consistent photoionized absorption model. In all but one case, two photoionization zones were required in order to obtain acceptable fits. Two independent constraints on launching radii, obtained via the ionization parameter formalism and the dynamical broadening of the re- emission, helped characterize the geometry of the wind. The innermost wind components (r≃ {10}2-3{GM}/{c}2) tend toward small volume filling factors, high ionization, densities up to n≃ {10}15-16 {cm}}-3, and outflow velocities of ∼0.003c. These small launching radii and large densities require magnetic driving, as they are inconsistent with numerical and analytical treatments of thermally driven winds. Outer wind components (r≃ {10}5{GM}/{c}2) are significantly less ionized and have filling factors near unity. Their larger launching radii, lower densities (n≃ {10}12 {cm}}-3), and outflow velocities (∼0.0007c) are nominally consistent with thermally driven winds. The overall wind structure suggests that these components may also be part of a broader MHD outflow and perhaps better described as magneto-thermal hybrid winds.
Fractional polarization of extragalactic sources in the 500 deg2 SPTpol surveyGupta, N.Reichardt, C. L.Ade, P. A. R.Anderson, A. J.Archipley, M.Austermann, J. E.Avva, J. S.Beall, J. A.Bender, A. N.Benson, B. A.Bianchini, F.Bleem, L. E.Carlstrom, J. E.Chang, C. L.Chiang, H. C.Citron, R.Moran, C. CorbettCrawford, T. M.Crites, A. T.de Haan, T.Dobbs, M. A.Everett, W.Feng, C.Gallicchio, J.George, E. M.Gilbert, A.Halverson, N. W.Harrington, N.Henning, J. W.Hilton, G. C.Holder, G. P.Holzapfel, W. L.Hou, Z.Hrubes, J. D.Huang, N.Hubmayr, J.Irwin, K. D.Knox, L.Lee, A. T.Li, D.Lowitz, A.Luong-Van, D.Marrone, D. P.McMahon, J. J.Meyer, S. S.Mocanu, L. M.Mohr, J. J.Montgomery, J.Nadolski, A.Natoli, T.Nibarger, J. P.Noble, G. I.Novosad, V.Padin, S.Patil, S.Pryke, C.Ruhl, J. E.Saliwanchik, B. R.Sayre, J. T.Schaffer, K. K.Shirokoff, E.Sievers, C.Smecher, G.Staniszewski, Z.Stark, Anthony A.Story, K. T.Switzer, E. R.Tucker, C.Vanderlinde, K.Veach, T.Vieira, J. D.Wang, G.Whitehorn, N.Williamson, R.Wu, W. L. K.Yefremenko, V.Zhang, L.2019DOI: info:10.1093/mnras/stz2905Monthly Notices of the Royal Astronomical Societyv. 490 5712 57215712–57210035-8711
Gupta, N., Reichardt, C. L., Ade, P. A. R., Anderson, A. J., Archipley, M., Austermann, J. E., Avva, J. S., Beall, J. A., Bender, A. N., Benson, B. A., Bianchini, F., Bleem, L. E., Carlstrom, J. E., Chang, C. L., Chiang, H. C., Citron, R., Moran, C. Corbett, Crawford, T. M., Crites, A. T., de Haan, T., Dobbs, M. A., Everett, W., Feng, C., Gallicchio, J., George, E. M. et al. 2019. "Fractional polarization of extragalactic sources in the 500 deg2 SPTpol survey." Monthly Notices of the Royal Astronomical Society 490: 5712– 5721. https://doi.org/10.1093/mnras/stz2905
ID: 154532
Type: article
Authors: Gupta, N.; Reichardt, C. L.; Ade, P. A. R.; Anderson, A. J.; Archipley, M.; Austermann, J. E.; Avva, J. S.; Beall, J. A.; Bender, A. N.; Benson, B. A.; Bianchini, F.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Chiang, H. C.; Citron, R.; Moran, C. Corbett; Crawford, T. M.; Crites, A. T.; de Haan, T.; Dobbs, M. A.; Everett, W.; Feng, C.; Gallicchio, J.; George, E. M.; Gilbert, A.; Halverson, N. W.; Harrington, N.; Henning, J. W.; Hilton, G. C.; Holder, G. P.; Holzapfel, W. L.; Hou, Z.; Hrubes, J. D.; Huang, N.; Hubmayr, J.; Irwin, K. D.; Knox, L.; Lee, A. T.; Li, D.; Lowitz, A.; Luong-Van, D.; Marrone, D. P.; McMahon, J. J.; Meyer, S. S.; Mocanu, L. M.; Mohr, J. J.; Montgomery, J.; Nadolski, A.; Natoli, T.; Nibarger, J. P.; Noble, G. I.; Novosad, V.; Padin, S.; Patil, S.; Pryke, C.; Ruhl, J. E.; Saliwanchik, B. R.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Sievers, C.; Smecher, G.; Staniszewski, Z.; Stark, Anthony A.; Story, K. T.; Switzer, E. R.; Tucker, C.; Vanderlinde, K.; Veach, T.; Vieira, J. D.; Wang, G.; Whitehorn, N.; Williamson, R.; Wu, W. L. K.; Yefremenko, V.; Zhang, L.
Keywords: SAO
Abstract: We study the polarization properties of extragalactic sources at 95 and 150 GHz in the SPTpol 500 deg2 survey. We estimate the polarized power by stacking maps at known source positions, and correct for noise bias by subtracting the mean polarized power at random positions in the maps. We show that the method is unbiased using a set of simulated maps with similar noise properties to the real SPTpol maps. We find a flux-weighted mean-squared polarization fraction
2> = [8.9 ± 1.1] × 10-4 at 95 GHz and [6.9 ± 1.1] × 10-4 at 150 GHz for the full sample. This is consistent with the values obtained for a subsample of active galactic nuclei. For dusty sources, we find 95 per cent upper limits of
2>95 -3 and
2>150 -3. We find no evidence that the polarization fraction depends on the source flux or observing frequency. The 1σ upper limit on measured mean-squared polarization fraction at 150 GHz implies that extragalactic foregrounds will be subdominant to the CMB E and B mode polarization power spectra out to at least ℓ ≲ 5700 (ℓ ≲ 4700) and ℓ ≲ 5300 (ℓ ≲ 3600), respectively, at 95 (150) GHz.
Massive-star Formation via the Collapse of Subvirial and Virialized Turbulent Massive CoresRosen, Anna L.Li, Pak ShingZhang, QizhouBurkhart, Blakesley2019DOI: info:10.3847/1538-4357/ab54c6The Astrophysical Journalv. 887 108 1080004-637X
Rosen, Anna L., Li, Pak Shing, Zhang, Qizhou, and Burkhart, Blakesley. 2019. "Massive-star Formation via the Collapse of Subvirial and Virialized Turbulent Massive Cores." The Astrophysical Journal 887: 108. https://doi.org/10.3847/1538-4357/ab54c6
ID: 154533
Type: article
Authors: Rosen, Anna L.; Li, Pak Shing; Zhang, Qizhou; Burkhart, Blakesley
Keywords: SAO
Abstract: Similar to their low-mass counterparts, massive stars likely form via the collapse of prestellar molecular cores. Recent observations suggest that most massive cores are subvirial (i.e., not supported by turbulence) and therefore are likely unstable to gravitational collapse. Here we perform radiation-hydrodynamic simulations to follow the collapse of turbulent massive prestellar cores with subvirial and virialized initial conditions to explore how their dynamic state affects the formation of massive stars and core fragmentation into companion stars. We find that subvirial cores undergo rapid monolithic collapse, resulting in higher accretion rates at early times as compared to the collapse of virialized cores that have the same physical properties. In contrast, we find that virialized cores undergo a slower, gradual collapse and significant turbulent fragmentation at early times, resulting in numerous companion stars. In the absence of strong magnetic fields and protostellar outflows, we find that the faster growth rate of massive stars that are born out of subvirial cores leads to an increase in the radiative heating of the core, thereby further suppressing fragmentation at early times when turbulent fragmentation occurs for virialized cores. Regardless of initial condition, we find that the massive accretion disks that form around massive stars dominant the accretion flow onto the star at late times and eventually become gravitationally unstable and fragment to form companion stars at late times.
Improving the accuracy of simulated chaotic N-body orbits using smoothnessHernandez, David M.2019DOI: info:10.1093/mnras/stz2662Monthly Notices of the Royal Astronomical Societyv. 490 4175 41824175–41820035-8711
Hernandez, David M. 2019. "Improving the accuracy of simulated chaotic N-body orbits using smoothness." Monthly Notices of the Royal Astronomical Society 490: 4175– 4182. https://doi.org/10.1093/mnras/stz2662
ID: 154534
Type: article
Authors: Hernandez, David M.
Keywords: SAO
Abstract: Symplectic integrators are a foundation to the study of dynamical N-body phenomena, at scales ranging from planetary to cosmological. These integrators preserve the Poincaré invariants of Hamiltonian dynamics. The N-body Hamiltonian has another, perhaps overlooked, symmetry: it is smooth, or, in other words, it has infinite differentiability class order (DCO) for particle separations greater than 0. Popular symplectic integrators, such as hybrid methods or block adaptive stepping methods do not come from smooth Hamiltonians and it is perhaps unclear whether they should. We investigate the importance of this symmetry by considering hybrid integrators, whose DCO can be tuned easily. Hybrid methods are smooth, except at a finite number of phase space points. We study chaotic planetary orbits in a test considered by Wisdom. We find that increasing smoothness, at negligible extra computational cost in particular tests, improves the Jacobi constant error of the orbits by about 5 orders of magnitude in long-term simulations. The results from this work suggest that smoothness of the N-body Hamiltonian is a property worth preserving in simulations.
Search for RR Lyrae stars in DES ultrafaint systems: Grus I, Kim 2, Phoenix II, and Grus IIMartínez-Vázquez, C. E.Vivas, A. K.Gurevich, M.Walker, A. R.McCarthy, M.Pace, A. B.Stringer, K. M.Santiago, B.Hounsell, R.Macri, L.Li, T. S.Bechtol, K.Riley, A. H.Kim, A. G.Simon, J. D.Drlica-Wagner, A.Nadler, E. O.Marshall, J. L.Annis, J.Avila, S.Bertin, E.Brooks, D.Buckley-Geer, E.Burke, D. L.Carnero Rosell, A.Carrasco Kind, M.da Costa, L. N.De Vicente, J.Desai, S.Diehl, H. T.Doel, P.Everett, S.Frieman, J.García-Bellido, J.Gaztanaga, E.Gruen, D.Gruendl, R. A.Gschwend, J.Gutierrez, G.Hollowood, D. L.Honscheid, K.James, David J.Kuehn, K.Kuropatkin, N.Maia, M. A. G.Menanteau, F.Miller, C. J.Miquel, R.Paz-Chinchón, F.Plazas, A. A.Sanchez, E.Scarpine, V.Serrano, S.Sevilla-Noarbe, I.Smith, M.Soares-Santos, M.Sobreira, F.Swanson, M. E. C.Tarle, G.Vikram, V.DES Collaboration2019DOI: info:10.1093/mnras/stz2609Monthly Notices of the Royal Astronomical Societyv. 490 2183 21992183–21990035-8711
Martínez-Vázquez, C. E., Vivas, A. K., Gurevich, M., Walker, A. R., McCarthy, M., Pace, A. B., Stringer, K. M., Santiago, B., Hounsell, R., Macri, L., Li, T. S., Bechtol, K., Riley, A. H., Kim, A. G., Simon, J. D., Drlica-Wagner, A., Nadler, E. O., Marshall, J. L., Annis, J., Avila, S., Bertin, E., Brooks, D., Buckley-Geer, E., Burke, D. L., Carnero Rosell, A. et al. 2019. "Search for RR Lyrae stars in DES ultrafaint systems: Grus I, Kim 2, Phoenix II, and Grus II." Monthly Notices of the Royal Astronomical Society 490: 2183– 2199. https://doi.org/10.1093/mnras/stz2609
ID: 154535
Type: article
Authors: Martínez-Vázquez, C. E.; Vivas, A. K.; Gurevich, M.; Walker, A. R.; McCarthy, M.; Pace, A. B.; Stringer, K. M.; Santiago, B.; Hounsell, R.; Macri, L.; Li, T. S.; Bechtol, K.; Riley, A. H.; Kim, A. G.; Simon, J. D.; Drlica-Wagner, A.; Nadler, E. O.; Marshall, J. L.; Annis, J.; Avila, S.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; da Costa, L. N.; De Vicente, J.; Desai, S.; Diehl, H. T.; Doel, P.; Everett, S.; Frieman, J.; García-Bellido, J.; Gaztanaga, E.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Hollowood, D. L.; Honscheid, K.; James, David J.; Kuehn, K.; Kuropatkin, N.; Maia, M. A. G.; Menanteau, F.; Miller, C. J.; Miquel, R.; Paz-Chinchón, F.; Plazas, A. A.; Sanchez, E.; Scarpine, V.; Serrano, S.; Sevilla-Noarbe, I.; Smith, M.; Soares-Santos, M.; Sobreira, F.; Swanson, M. E. C.; Tarle, G.; Vikram, V.; DES Collaboration
Keywords: SAO
Abstract: This work presents the first search for RR Lyrae stars (RRLs) in four of the ultrafaint systems imaged by the Dark Energy Survey using SOAR/Goodman and Blanco/DECam imagers. We have detected two RRLs in the field of Grus I, none in Kim 2, one in Phoenix II, and four in Grus II. With the detection of these stars, we accurately determine the distance moduli for these ultrafaint dwarf satellite galaxies; μ0 = 20.51 ± 0.10 mag (D = 127 ± 6 kpc) for Grus I and μ0 = 20.01 ± 0.10 mag (D = 100 ± 5 kpc) for Phoenix II. These measurements are larger than previous estimations by Koposov et al. and Bechtol et al., implying larger physical sizes; 5 per cent for Grus I and 33 per cent for Phoenix II. For Grus II, of the four RRLs detected, one is consistent with being a member of the galactic halo (D = 24 ± 1 kpc, μ0 = 16.86 ± 0.10 mag), another is at D = 55 ± 2 kpc (μ0 = 18.71 ± 0.10 mag), which we associate with Grus II, and the two remaining at D = 43 ± 2 kpc (μ0 = 18.17 ± 0.10 mag). Moreover, the appearance of a subtle red horizontal branch in the colour-magnitude diagram of Grus II at the same brightness level of the latter two RRLs, which are at the same distance and in the same region, suggests that a more metal-rich system may be located in front of Grus II. The most plausible scenario is the association of these stars with the Chenab/Orphan Stream. Finally, we performed a comprehensive and updated analysis of the number of RRLs in dwarf galaxies. This allows us to predict that the method of finding new ultrafaint dwarf galaxies using two or more clumped RRLs will work only for systems brighter than MV ̃ -6 mag.
Combined Effects of Rotation and Age Spreads on Extended Main-Sequence Turn OffsGossage, SethConroy, CharlieDotter, AaronCabrera-Ziri, IvanDolphin, Andrew E.Bastian, NateDalcanton, Julianne J.Goudfrooij, PaulJohnson, L. CliftonWilliams, Benjamin F.Rosenfield, PhilipKalirai, JasonFouesneau, Morgan2019DOI: info:10.3847/1538-4357/ab5717The Astrophysical Journalv. 887 199 1990004-637X
Gossage, Seth, Conroy, Charlie, Dotter, Aaron, Cabrera-Ziri, Ivan, Dolphin, Andrew E., Bastian, Nate, Dalcanton, Julianne J., Goudfrooij, Paul, Johnson, L. Clifton, Williams, Benjamin F., Rosenfield, Philip, Kalirai, Jason, and Fouesneau, Morgan. 2019. "Combined Effects of Rotation and Age Spreads on Extended Main-Sequence Turn Offs." The Astrophysical Journal 887: 199. https://doi.org/10.3847/1538-4357/ab5717
ID: 154536
Type: article
Authors: Gossage, Seth; Conroy, Charlie; Dotter, Aaron; Cabrera-Ziri, Ivan; Dolphin, Andrew E.; Bastian, Nate; Dalcanton, Julianne J.; Goudfrooij, Paul; Johnson, L. Clifton; Williams, Benjamin F.; Rosenfield, Philip; Kalirai, Jason; Fouesneau, Morgan
Keywords: SAO
Abstract: The extended main-sequence turn offs (eMSTOs) of several young to intermediate age clusters are examined in the Magellanic Clouds and the Milky Way. We explore the effects of extended star formation (eSF) and a range of stellar rotation rates on the behavior of the color─magnitude diagram, paying particular attention to the MSTO. We create synthetic stellar populations based on MESA stellar models to simulate observed Hubble Space Telescope and Gaia star cluster data. We model the effect of rotation as a nonparametric distribution, allowing for maximum flexibility. In our models the slow rotators comprise the blueward, and fast rotators the redward portion of the eMSTO. We simulate data under three scenarios: nonrotating eSF, a range of rotation rates with a single age, and a combination of age and rotation effects. We find that two of the five clusters (the youngest and oldest) favor an age spread, but these also achieve the overall worst fits of all clusters. The other three clusters show comparable statistical evidence between rotation and an age spread. In all five cases, a rotation-rate distribution alone is capable of qualitatively matching the observed eMSTO structure. In future work, we aim to compare our predicted V\sin i with observations in order to better constrain the physics related to stellar rotation.
Constraining the Neutron Star Mass─Radius Relation and Dense Matter Equation of State with NICER. I. The Millisecond Pulsar X-Ray Data SetBogdanov, SlavkoGuillot, SebastienRay, Paul S.Wolff, Michael T.Chakrabarty, DeeptoHo, Wynn C. G.Kerr, MatthewLamb, Frederick K.Lommen, AndreaLudlam, Renee M.Milburn, ReillyMontano, SergioMiller, M. ColemanBauböck, MichiÖzel, FeryalPsaltis, DimitriosRemillard, Ronald A.Riley, Thomas E.Steiner, James F.Strohmayer, Tod E.Watts, Anna L.Wood, Kent S.Zeldes, JesseEnoto, TeruakiOkajima, TakashiKellogg, James W.Baker, CharlesMarkwardt, Craig B.Arzoumanian, ZavenGendreau, Keith C.2019DOI: info:10.3847/2041-8213/ab53ebThe Astrophysical Journalv. 887 L25 L250004-637X
Bogdanov, Slavko, Guillot, Sebastien, Ray, Paul S., Wolff, Michael T., Chakrabarty, Deepto, Ho, Wynn C. G., Kerr, Matthew, Lamb, Frederick K., Lommen, Andrea, Ludlam, Renee M., Milburn, Reilly, Montano, Sergio, Miller, M. Coleman, Bauböck, Michi, Özel, Feryal, Psaltis, Dimitrios, Remillard, Ronald A., Riley, Thomas E., Steiner, James F., Strohmayer, Tod E., Watts, Anna L., Wood, Kent S., Zeldes, Jesse, Enoto, Teruaki, Okajima, Takashi et al. 2019. "Constraining the Neutron Star Mass─Radius Relation and Dense Matter Equation of State with NICER. I. The Millisecond Pulsar X-Ray Data Set." The Astrophysical Journal 887: L25. https://doi.org/10.3847/2041-8213/ab53eb
ID: 154537
Type: article
Authors: Bogdanov, Slavko; Guillot, Sebastien; Ray, Paul S.; Wolff, Michael T.; Chakrabarty, Deepto; Ho, Wynn C. G.; Kerr, Matthew; Lamb, Frederick K.; Lommen, Andrea; Ludlam, Renee M.; Milburn, Reilly; Montano, Sergio; Miller, M. Coleman; Bauböck, Michi; Özel, Feryal; Psaltis, Dimitrios; Remillard, Ronald A.; Riley, Thomas E.; Steiner, James F.; Strohmayer, Tod E.; Watts, Anna L.; Wood, Kent S.; Zeldes, Jesse; Enoto, Teruaki; Okajima, Takashi; Kellogg, James W.; Baker, Charles; Markwardt, Craig B.; Arzoumanian, Zaven; Gendreau, Keith C.
Keywords: SAO
Abstract: We present the set of deep Neutron Star Interior Composition Explorer (NICER) X-ray timing observations of the nearby rotation-powered millisecond pulsars PSRs J0437−4715, J0030+0451, J1231−1411, and J2124−3358, selected as targets for constraining the mass─radius relation of neutron stars and the dense matter equation of state (EoS) via modeling of their pulsed thermal X-ray emission. We describe the instrument, observations, and data processing/reduction procedures, as well as the series of investigations conducted to ensure that the properties of the data sets are suitable for parameter estimation analyses to produce reliable constraints on the neutron star mass─radius relation and the dense matter EoS. We find that the long-term timing and flux behavior and the Fourier-domain properties of the event data do not exhibit any anomalies that could adversely affect the intended measurements. From phase-selected spectroscopy, we find that emission from the individual pulse peaks is well described by a single- temperature hydrogen atmosphere spectrum, with the exception of PSR J0437−4715, for which multiple temperatures are required.
The most luminous blue quasars at 3.0 < z < 3.3. I. A tale of two X-ray populationsNardini, E.Lusso, E.Risaliti, G.Bisogni, S.Civano, FrancescaElvis, MartinFabbiano, GiuseppinaGilli, R.Marconi, A.Salvestrini, F.Vignali, C.2019DOI: info:10.1051/0004-6361/201936911Astronomy and Astrophysicsv. 632 A109 A1090004-6361
Nardini, E., Lusso, E., Risaliti, G., Bisogni, S., Civano, Francesca, Elvis, Martin, Fabbiano, Giuseppina, Gilli, R., Marconi, A., Salvestrini, F., and Vignali, C. 2019. "The most luminous blue quasars at 3.0 < z < 3.3. I. A tale of two X-ray populations." Astronomy and Astrophysics 632: A109. https://doi.org/10.1051/0004-6361/201936911
ID: 154538
Type: article
Authors: Nardini, E.; Lusso, E.; Risaliti, G.; Bisogni, S.; Civano, Francesca; Elvis, Martin; Fabbiano, Giuseppina; Gilli, R.; Marconi, A.; Salvestrini, F.; Vignali, C.
Keywords: SAO
Abstract: We present the X-ray analysis of 30 luminous quasars at z ≃ 3.0 - 3.3 with pointed XMM-Newton observations (28-48 ks) originally obtained by our group to test the suitability of active galactic nuclei as standard candles for cosmological studies. The sample was selected in the optical from the Sloan Digital Sky Survey Data Release 7 to be representative of the most luminous, intrinsically blue quasar population, and by construction boasts a high degree of homogeneity in terms of optical and UV properties. In the X-rays, only four sources are too faint for a detailed spectral analysis, one of which is formally undetected. Neglecting one more object later found to be radio-loud, the other 25 quasars are, as a whole, the most X-ray luminous ever observed, with rest-frame 2-10 keV luminosities of 0.5 - 7 × 1045 erg s-1. The continuum photon index distribution, centred at Γ ̃ 1.85, is in excellent agreement with those in place at lower redshift, luminosity, and black-hole mass, confirming the universal nature of the X-ray emission mechanism in quasars. Even so, when compared against the well-known LX-LUV correlation, our quasars show an unexpectedly varied behaviour, splitting into two distinct subsets. About two-thirds of the sources are clustered around the relation with a minimal scatter of 0.1 dex, while the remaining one-third appear to be X-ray underluminous by factors of > 3-10. Such a large incidence (≈25%) of X-ray weakness has never been reported in radio-quiet, non- broad absorption line (BAL) quasar samples. Several factors could contribute to enhancing the X-ray weakness fraction among our z ≃ 3 blue quasars, including variability, mild X-ray obscuration, contamination from weak-line quasars, and missed BALs. However, the X-ray weak objects also have, on average, flatter spectra, with no clear evidence of absorption. Indeed, column densities in excess of a few ×1022 cm-2 can be ruled out for most of the sample. We suggest that, at least in some of our X-ray weak quasars, the corona might experience a radiatively inefficient phase due to the presence of a powerful accretion-disc wind, which substantially reduces the accretion rate through the inner disc and therefore also the availability of seed photons for Compton up-scattering. The origin of the deviations from the LX-LUV relation will be further investigated in a series of future studies.
Deep Chandra Survey of the Small Magellanic Cloud. III. Formation Efficiency of High-mass X-Ray BinariesAntoniou, ValliaZezas, AndreasDrake, Jeremy J.Badenes, CarlesHaberl, FrankWright, Nicholas J.Hong, JaesubDi Stefano, RosanneGaetz, Terrance J.Long, Knox S.Plucinsky, Paul P.Sasaki, ManamiWilliams, Benjamin F.Winkler, P. FrankSMC XVP collaboration2019DOI: info:10.3847/1538-4357/ab4a7aThe Astrophysical Journalv. 887 20 200004-637X
Antoniou, Vallia, Zezas, Andreas, Drake, Jeremy J., Badenes, Carles, Haberl, Frank, Wright, Nicholas J., Hong, Jaesub, Di Stefano, Rosanne, Gaetz, Terrance J., Long, Knox S., Plucinsky, Paul P., Sasaki, Manami, Williams, Benjamin F., Winkler, P. Frank, and SMC XVP collaboration. 2019. "Deep Chandra Survey of the Small Magellanic Cloud. III. Formation Efficiency of High-mass X-Ray Binaries." The Astrophysical Journal 887: 20. https://doi.org/10.3847/1538-4357/ab4a7a
ID: 154539
Type: article
Authors: Antoniou, Vallia; Zezas, Andreas; Drake, Jeremy J.; Badenes, Carles; Haberl, Frank; Wright, Nicholas J.; Hong, Jaesub; Di Stefano, Rosanne; Gaetz, Terrance J.; Long, Knox S.; Plucinsky, Paul P.; Sasaki, Manami; Williams, Benjamin F.; Winkler, P. Frank; SMC XVP collaboration
Keywords: SAO
Abstract: We have compiled the most complete census of high-mass X-ray binaries (HMXBs) in the Small Magellanic Cloud with the aim to investigate the formation efficiency of young accreting binaries in its low-metallicity environment. In total, we use 123 X-ray sources with detections in our Chandra X-ray Visionary Program (XVP), supplemented by 14 additional (likely and confirmed) HMXBs identified by Haberl & Sturm that fall within the XVP area, but are neither detected in our survey (nine sources) nor matched with any of the 127 sources identified in the XVP data (five sources). Specifically, we examine the number ratio of the HMXBs [N(HMXBs)] to (a) the number of OB stars, (b) the local star formation rate (SFR), and (c) the stellar mass produced during the specific star formation burst, all as a function of the age of their parent stellar populations. Each of these indicators serves a different role, but in all cases we find that the HMXB formation efficiency increases as a function of time (following a burst of star formation) up to ∼40─60 Myr, and then gradually decreases. The formation efficiency peaks at ∼30─40 Myr with average rates of {\text{}}{{N}}({HMXB})/{SFR}={339}-83+78 {({M}ȯ /{yr})}-1, and N(HMXB)/M \star =({8.74}-0.92+1.0)× {10}-6 {M}ȯ -1, in good agreement with previous estimates of the average formation efficiency in the broad ∼20─60 Myr age range.
OCCASO - III. Iron peak and α elements of 18 open clusters. Comparison with chemical evolution models and field starsCasamiquela, L.Blanco-Cuaresma, SergiCarrera, R.Balaguer-Núñez, L.Jordi, C.Anders, F.Chiappini, C.Carbajo-Hijarrubia, J.Aguado, D. S.del Pino, A.Díaz-Pérez, L.Gallart, C.Pancino, E.2019DOI: info:10.1093/mnras/stz2595Monthly Notices of the Royal Astronomical Societyv. 490 1821 18421821–18420035-8711
Casamiquela, L., Blanco-Cuaresma, Sergi, Carrera, R., Balaguer-Núñez, L., Jordi, C., Anders, F., Chiappini, C., Carbajo-Hijarrubia, J., Aguado, D. S., del Pino, A., Díaz-Pérez, L., Gallart, C., and Pancino, E. 2019. "OCCASO - III. Iron peak and α elements of 18 open clusters. Comparison with chemical evolution models and field stars." Monthly Notices of the Royal Astronomical Society 490: 1821– 1842. https://doi.org/10.1093/mnras/stz2595
ID: 154540
Type: article
Authors: Casamiquela, L.; Blanco-Cuaresma, Sergi; Carrera, R.; Balaguer-Núñez, L.; Jordi, C.; Anders, F.; Chiappini, C.; Carbajo-Hijarrubia, J.; Aguado, D. S.; del Pino, A.; Díaz-Pérez, L.; Gallart, C.; Pancino, E.
Keywords: SAO
Abstract: The study of open-cluster chemical abundances provides insights on stellar nucleosynthesis processes and on Galactic chemo-dynamical evolution. In this paper we present an extended abundance analysis of 10 species (Fe, Ni, Cr, V, Sc, Si, Ca, Ti, Mg, O) for red giant stars in 18 OCCASO clusters. This represents a homogeneous sample regarding the instrument features, method, line list and solar abundances from confirmed member stars. We perform an extensive comparison with previous results in the literature, and in particular with the Gaia FGK Benchmark stars Arcturus and μ-Leo. We investigate the dependence of [X/Fe] with metallicity, Galactocentric radius (6.5 kpc GC GC and |z| obtained for clusters and for field stars.
The first view of δ Scuti and γ Doradus stars with the TESS missionAntoci, V.Cunha, M. S.Bowman, D. M.Murphy, S. J.Kurtz, D. W.Bedding, T. R.Borre, C. C.Christophe, S.Daszyńska-Daszkiewicz, J.Fox-Machado, L.García Hernández, A.Ghasemi, H.Handberg, R.Hansen, H.Hasanzadeh, A.Houdek, G.Johnston, C.Justesen, A. B.Kahraman Alicavus, F.Kotysz, K.Latham, DavidMatthews, J. M.Mønster, J.Niemczura, E.Paunzen, E.Sánchez Arias, J. P.Pigulski, A.Pepper, J.Richey-Yowell, T.Safari, H.Seager, S.Smalley, B.Shutt, T.Sódor, A.Suárez, J. -CTkachenko, A.Wu, T.Zwintz, K.Barceló Forteza, S.Brunsden, E.Bognár, Z.Buzasi, D. L.Chowdhury, S.De Cat, P.Evans, J. A.Guo, Z.Guzik, J. A.Jevtic, N.Lampens, P.Lares Martiz, M.Lovekin, C.Li, G.Mirouh, G. M.Mkrtichian, D.Monteiro, M. J. P. F. G.Nemec, J. M.Ouazzani, R. -MPascual-Granado, J.Reese, D. R.Rieutord, M.Rodon, J. R.Skarka, M.Sowicka, P.Stateva, I.Szabó, R.Weiss, W. W.2019DOI: info:10.1093/mnras/stz2787Monthly Notices of the Royal Astronomical Societyv. 490 4040 40594040–40590035-8711
Antoci, V., Cunha, M. S., Bowman, D. M., Murphy, S. J., Kurtz, D. W., Bedding, T. R., Borre, C. C., Christophe, S., Daszyńska-Daszkiewicz, J., Fox-Machado, L., García Hernández, A., Ghasemi, H., Handberg, R., Hansen, H., Hasanzadeh, A., Houdek, G., Johnston, C., Justesen, A. B., Kahraman Alicavus, F., Kotysz, K., Latham, David, Matthews, J. M., Mønster, J., Niemczura, E., Paunzen, E. et al. 2019. "The first view of δ Scuti and γ Doradus stars with the TESS mission." Monthly Notices of the Royal Astronomical Society 490: 4040– 4059. https://doi.org/10.1093/mnras/stz2787
ID: 154541
Type: article
Authors: Antoci, V.; Cunha, M. S.; Bowman, D. M.; Murphy, S. J.; Kurtz, D. W.; Bedding, T. R.; Borre, C. C.; Christophe, S.; Daszyńska-Daszkiewicz, J.; Fox-Machado, L.; García Hernández, A.; Ghasemi, H.; Handberg, R.; Hansen, H.; Hasanzadeh, A.; Houdek, G.; Johnston, C.; Justesen, A. B.; Kahraman Alicavus, F.; Kotysz, K.; Latham, David; Matthews, J. M.; Mønster, J.; Niemczura, E.; Paunzen, E.; Sánchez Arias, J. P.; Pigulski, A.; Pepper, J.; Richey-Yowell, T.; Safari, H.; Seager, S.; Smalley, B.; Shutt, T.; Sódor, A.; Suárez, J. -C; Tkachenko, A.; Wu, T.; Zwintz, K.; Barceló Forteza, S.; Brunsden, E.; Bognár, Z.; Buzasi, D. L.; Chowdhury, S.; De Cat, P.; Evans, J. A.; Guo, Z.; Guzik, J. A.; Jevtic, N.; Lampens, P.; Lares Martiz, M.; Lovekin, C.; Li, G.; Mirouh, G. M.; Mkrtichian, D.; Monteiro, M. J. P. F. G.; Nemec, J. M.; Ouazzani, R. -M; Pascual-Granado, J.; Reese, D. R.; Rieutord, M.; Rodon, J. R.; Skarka, M.; Sowicka, P.; Stateva, I.; Szabó, R.; Weiss, W. W.
Keywords: SAO
Abstract: We present the first asteroseismic results for δ Scuti and γ Doradus stars observed in Sectors 1 and 2 of the TESS mission. We utilize the 2-min cadence TESS data for a sample of 117 stars to classify their behaviour regarding variability and place them in the Hertzsprung- Russell diagram using Gaia DR2 data. Included within our sample are the eponymous members of two pulsator classes, γ Doradus and SX Phoenicis. Our sample of pulsating intermediate-mass stars observed by TESS also allows us to confront theoretical models of pulsation driving in the classical instability strip for the first time and show that mixing processes in the outer envelope play an important role. We derive an empirical estimate of 74 per cent for the relative amplitude suppression factor as a result of the redder TESS passband compared to the Kepler mission using a pulsating eclipsing binary system. Furthermore, our sample contains many high-frequency pulsators, allowing us to probe the frequency variability of hot young δ Scuti stars, which were lacking in the Kepler mission data set, and identify promising targets for future asteroseismic modelling. The TESS data also allow us to refine the stellar parameters of SX Phoenicis, which is believed to be a blue straggler.
The KMOS3D Survey: Data Release and Final Survey PaperWisnioski, E.Förster Schreiber, N. M.Fossati, M.Mendel, J. T.Wilman, D.Genzel, R.Bender, R.Wuyts, S.Davies, R. L.Übler, H.Bandara, K.Beifiori, A.Belli, S.Brammer, G.Chan, J.Davies, R. I.Fabricius, M.Galametz, A.Lang, P.Lutz, D.Nelson, Erica J.Momcheva, I.Price, S.Rosario, D.Saglia, R.Seitz, S.Shimizu, T.Tacconi, L. J.Tadaki, K.van Dokkum, P. G.Wuyts, E.2019DOI: info:10.3847/1538-4357/ab4db8The Astrophysical Journalv. 886 124 1240004-637X
Wisnioski, E., Förster Schreiber, N. M., Fossati, M., Mendel, J. T., Wilman, D., Genzel, R., Bender, R., Wuyts, S., Davies, R. L., Übler, H., Bandara, K., Beifiori, A., Belli, S., Brammer, G., Chan, J., Davies, R. I., Fabricius, M., Galametz, A., Lang, P., Lutz, D., Nelson, Erica J., Momcheva, I., Price, S., Rosario, D., Saglia, R. et al. 2019. "The KMOS3D Survey: Data Release and Final Survey Paper." The Astrophysical Journal 886: 124. https://doi.org/10.3847/1538-4357/ab4db8
ID: 154542
Type: article
Authors: Wisnioski, E.; Förster Schreiber, N. M.; Fossati, M.; Mendel, J. T.; Wilman, D.; Genzel, R.; Bender, R.; Wuyts, S.; Davies, R. L.; Übler, H.; Bandara, K.; Beifiori, A.; Belli, S.; Brammer, G.; Chan, J.; Davies, R. I.; Fabricius, M.; Galametz, A.; Lang, P.; Lutz, D.; Nelson, Erica J.; Momcheva, I.; Price, S.; Rosario, D.; Saglia, R.; Seitz, S.; Shimizu, T.; Tacconi, L. J.; Tadaki, K.; van Dokkum, P. G.; Wuyts, E.
Keywords: SAO
Abstract: We present the completed KMOS3D survey, an integral field spectroscopic survey of 739 {log}({M}\star /{M}ȯ )> 9 galaxies at 0.6 )> 9 galaxies at 0.6 )> 9 galaxies at 0.6 3D survey provides a population-wide census of kinematics, star formation, outflows, and nebular gas conditions both on and off the star-forming galaxy main sequence through the spatially resolved and integrated properties of Hα, [N II], and [S II] emission lines. We detect Hα emission for 91% of galaxies on the main sequence of star formation and 79% overall. The depth of the survey has allowed us to detect galaxies with star formation rates below 1 M yr−1, as well as to resolve 81% of detected galaxies with ≥3 resolution elements along the kinematic major axis. The detection fraction of Hα is a strong function of both color and offset from the main sequence, with the detected and nondetected samples exhibiting different spectral energy distribution shapes. Comparison of Hα and UV+IR star formation rates reveal that dust attenuation corrections may be underestimated by 0.5 dex at the highest masses ({log}({M}\star /{M}ȯ )> 10.5). We confirm our first year results of a high rotation-dominated fraction (monotonic velocity gradient and v rot/{σ }0> \sqrt{3.36}) of 77% for the full KMOS3D sample. The rotation-dominated fraction is a function of both stellar mass and redshift, with the strongest evolution measured over the redshift range of the survey for galaxies with {log}({M}\star /{M}ȯ ))http://www.mpe.mpg.de/ir/KMOS3D). Based on observations obtained at the Very Large Telescope (VLT) of the European Southern Observatory (ESO), Paranal, Chile (ESO program IDS 092A-0091, 093.A-0079, 093.A-0079, 094.A-0217, 095.A-0047, 096.A-0025, 097.A-0028, 098.A-0045, 099.A-0013, 0100.A-0039, and 0101.A-0022).
Electron Energy Partition across Interplanetary Shocks. II. StatisticsWilson, Lynn B., IIIChen, Li-JenWang, ShanSchwartz, Steven J.Turner, Drew L.Stevens, Michael L.Kasper, Justin C.Osmane, AdnaneCaprioli, DamianoBale, Stuart D.Pulupa, Marc P.Salem, Chadi S.Goodrich, Katherine A.2019DOI: info:10.3847/1538-4365/ab5445The Astrophysical Journal Supplement Seriesv. 245 24 240067-0049
Wilson, Lynn B., III, Chen, Li-Jen, Wang, Shan, Schwartz, Steven J., Turner, Drew L., Stevens, Michael L., Kasper, Justin C., Osmane, Adnane, Caprioli, Damiano, Bale, Stuart D., Pulupa, Marc P., Salem, Chadi S., and Goodrich, Katherine A. 2019. "Electron Energy Partition across Interplanetary Shocks. II. Statistics." The Astrophysical Journal Supplement Series 245: 24. https://doi.org/10.3847/1538-4365/ab5445
ID: 154543
Type: article
Authors: Wilson, Lynn B., III; Chen, Li-Jen; Wang, Shan; Schwartz, Steven J.; Turner, Drew L.; Stevens, Michael L.; Kasper, Justin C.; Osmane, Adnane; Caprioli, Damiano; Bale, Stuart D.; Pulupa, Marc P.; Salem, Chadi S.; Goodrich, Katherine A.
Keywords: SAO
Abstract: A statistical analysis of 15,210 electron velocity distribution function (VDF) fits, observed within ±2 hr of 52 interplanetary (IP) shocks by the Wind spacecraft near 1 au, is presented. This is the second in a three-part series on electron VDFs near IP shocks. The electron velocity moment statistics for the dense, low-energy core, tenuous, hot halo, and field-aligned beam/strahl are a statistically significant list of values illustrated with both histograms and tabular lists for reference and baselines in future work. Given the large statistics in this investigation, the beam/strahl fit results in the upstream are now the most comprehensive attempt to parameterize the beam/strahl electron velocity moments in the ambient solar wind. The median density, temperature, beta, and temperature anisotropy values for the core(halo)[beam/strahl] components, with subscripts ec(eh)[eb], of all fit results, respectively, are {n}ec(h)[b]}∼ 11.3(0.36)[0.17] {cm}}-3, {T}ec(h)[b],{tot}}∼ 14.6(48.4)[40.2] {eV}, {β }ec(h)[b],{tot}}∼ 0.93(0.11)[0.05], and {{ \mathcal A }}ec(h)[b]} ∼ 0.98(1.03)[0.93]. This work will also serve as a 1 au baseline and reference for missions like Parker Solar Probe and Solar Orbiter.
Eclipsing Binaries in the Open Cluster Ruprecht 147. II. Epic 219568666Torres, GuillermoVanderburg, AndrewCurtis, Jason L.Ciardi, DavidKraus, Adam L.Rizzuto, Aaron C.Ireland, Michael J.Lund, Michael B.Christiansen, Jessie L.Beichman, Charles A.2019DOI: info:10.3847/1538-4357/ab54c5The Astrophysical Journalv. 887 109 1090004-637X
Torres, Guillermo, Vanderburg, Andrew, Curtis, Jason L., Ciardi, David, Kraus, Adam L., Rizzuto, Aaron C., Ireland, Michael J., Lund, Michael B., Christiansen, Jessie L., and Beichman, Charles A. 2019. "Eclipsing Binaries in the Open Cluster Ruprecht 147. II. Epic 219568666." The Astrophysical Journal 887: 109. https://doi.org/10.3847/1538-4357/ab54c5
ID: 154544
Type: article
Authors: Torres, Guillermo; Vanderburg, Andrew; Curtis, Jason L.; Ciardi, David; Kraus, Adam L.; Rizzuto, Aaron C.; Ireland, Michael J.; Lund, Michael B.; Christiansen, Jessie L.; Beichman, Charles A.
Keywords: SAO
Abstract: We report our spectroscopic monitoring of the detached, grazing, and slightly eccentric 12 day double-lined eclipsing binary EPIC 219568666 in the old nearby open cluster Ruprecht 147. This is the second eclipsing system to be analyzed in t