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The Destruction and Recreation of the X-Ray Corona in a Changing-look Active Galactic NucleusRicci, C.Kara, E.Loewenstein, M.Trakhtenbrot, B.Arcavi, I.Remillard, R.Fabian, A. C.Gendreau, K. C.Arzoumanian, Z.Li, R.Ho, L. C.MacLeod, Chelsea L.Cackett, E.Altamirano, D.Gandhi, P.Kosec, P.Pasham, D.Steiner, JamesChan, C. -HDOI: info:10.3847/2041-8213/ab91a1v. 898L1
Ricci, C., Kara, E., Loewenstein, M., Trakhtenbrot, B., Arcavi, I., Remillard, R., Fabian, A. C., Gendreau, K. C., Arzoumanian, Z., Li, R., Ho, L. C., MacLeod, Chelsea L., Cackett, E., Altamirano, D., Gandhi, P., Kosec, P., Pasham, D., Steiner, James, and Chan, C. -H. 2020. "The Destruction and Recreation of the X-Ray Corona in a Changing-look Active Galactic Nucleus." The Astrophysical Journal 898:L1. https://doi.org/10.3847/2041-8213/ab91a1
ID: 157794
Type: article
Authors: Ricci, C.; Kara, E.; Loewenstein, M.; Trakhtenbrot, B.; Arcavi, I.; Remillard, R.; Fabian, A. C.; Gendreau, K. C.; Arzoumanian, Z.; Li, R.; Ho, L. C.; MacLeod, Chelsea L.; Cackett, E.; Altamirano, D.; Gandhi, P.; Kosec, P.; Pasham, D.; Steiner, James; Chan, C. -H
Abstract: We present the drastic transformation of the X-ray properties of the active galactic nucleus (AGN) 1ES 1927+654, following a changing-look event. After the optical/ultraviolet outburst the power-law component, produced in the X-ray corona, disappeared, and the spectrum of 1ES 1927+65 instead became dominated by a blackbody component (kT ∼ 80-120 eV). This implies that the X-ray corona, ubiquitously found in AGNs, was destroyed in the event. Our dense ∼450 days long X-ray monitoring shows that the source is extremely variable in the X-ray band. On long timescales the source varies up to ∼4 dex in ∼100 days, while on short timescales up to ∼2 dex in ∼8 hr. The luminosity of the source is found to first show a strong dip down to $\sim {10}^{40}\,\mathrm{erg}\,{{\rm{s}}}^{-1}$?--> , and then a constant increase in luminosity to levels exceeding the pre-outburst level ≳300 days after the optical event detection, rising up asymptotically to $\sim 2\times {10}^{44}\,\mathrm{erg}\,{{\rm{s}}}^{-1}$?--> . As the X-ray luminosity of the source increases, the X-ray corona is recreated, and a very steep power-law component (Γ ≃ 3) reappears, and dominates the emission for 0.3-2 keV luminosities $\gtrsim {10}^{43.7}\,\mathrm{erg}\,{{\rm{s}}}^{-1}$?--> , ∼300 days after the beginning of the event. We discuss possible origins of this event, and speculate that our observations could be explained by the interaction between the accretion flow and debris from a tidally disrupted star. Our results show that changing-look events can be associated with dramatic and rapid transformations of the innermost regions of accreting supermassive black holes.
The 16th Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS SpectraAhumada, RominaAllende Prieto, CarlosAlmeida, AndrésAnders, FriedrichAnderson, Scott F.Andrews, Brett H.Anguiano, BorjaArcodia, RiccardoArmengaud, EricAubert, MarieAvila, SantiagoAvila-Reese, VladimirBadenes, CarlesBalland, ChristopheBarger, KatBarrera-Ballesteros, Jorge K.Basu, SarbaniBautista, JulianBeaton, Rachael L.Beers, Timothy C.Benavides, B. Izamar T.Bender, Chad F.Bernardi, MariangelaBershady, MatthewBeutler, FlorianBidin, Christian MoniBird, JonathanBizyaev, DmitryBlanc, Guillermo A.Blanton, Michael R.Boquien, MédéricBorissova, JuraBovy, JoBrandt, W. N.Brinkmann, JonathanBrownstein, Joel R.Bundy, KevinBureau, MartinBurgasser, AdamBurtin, EtienneCano-Díaz, MarianaCapasso, RaffaellaCappellari, MicheleCarrera, RicardoChabanier, SolèneChaplin, WilliamChapman, MichaelCherinka, BrianChiappini, CristinaDoohyun Choi, PeterChojnowski, S. DrewChung, HaeunClerc, NicolasCoffey, DamienComerford, Julia M.Comparat, Johanda Costa, LuizCousinou, Marie-ClaudeCovey, KevinCrane, Jeffrey D.Cunha, Katiada Silva Ilha, GabrieleDai, Yu SophiaDamsted, Sanna B.Darling, JeremyDavidson, James W., Jr.Davies, RogerDawson, KyleDe, Nikhilde la Macorra, AxelDe Lee, Nathande Andrade Queiroz, Anna BárbaraDeconto Machado, Alicede la Torre, SylvainDell'Agli, Flaviadu Mas des Bourboux, HélionDiamond-Stanic, Aleksandar M.Dillon, SeanDonor, JohnDrory, NivDuckworth, ChrisDwelly, TomEbelke, GarrettEftekharzadeh, SarahEigenbrot, Arthur DavisElsworth, Yvonne P.Eracleous, MikeErfanianfar, GhazalehEscoffier, StephanieFan, XiaohuiFarr, EmilyFernández-Trincado, José G.Feuillet, DianeFinoguenov, AlexisFofie, PatriciaFraser-McKelvie, AmeliaFrinchaboy, Peter M.Fromenteau, SebastienFu, HaiGalbany, LluísGarcia, Rafael A.García-Hernández, D. A.Garma Oehmichen, Luis AlbertoGe, JunqiangGeimba Maia, Marcio AntonioGeisler, DougGelfand, JosephGoddy, JulianGonzalez-Perez, VioletaGrabowski, KathleenGreen, PaulGrier, Catherine J.Guo, HongGuy, JulienHarding, PaulHasselquist, StenHawken, Adam JamesHayes, Christian R.Hearty, FredHekker, S.Hogg, David W.Holtzman, Jon A.Horta, DannyHou, JiaminHsieh, Bau-ChingHuber, DanielHunt, Jason A. S.Ider Chitham, J.Imig, JulieJaber, MarianaJimenez Angel, Camilo EduardoJohnson, Jennifer A.Jones, Amy M.Jönsson, HenrikJullo, EricKim, YerimKinemuchi, KarenKirkpatrick, Charles C.,IVKite, George W.Klaene, MarkKneib, Jean-PaulKollmeier, Juna A.Kong, HuiKounkel, MarinaKrishnarao, DhaneshLacerna, IvanLan, Ting-WenLane, Richard R.Law, David R.Le Goff, Jean-MarcLeung, Henry W.Lewis, HannahLi, ChengLian, JianhuiLin, LihwaiLong, DanLonga-Peña, PenélopeLundgren, BrittLyke, Brad W.Ted Mackereth, J.MacLeod, Chelsea L.Majewski, Steven R.Manchado, ArturoMaraston, ClaudiaMartini, PaulMasseron, ThomasMasters, Karen L.Mathur, SavitaMcDermid, Richard M.Merloni, AndreaMerrifield, MichaelMészáros, SzabolcsMiglio, AndreaMinniti, DanteMinsley, RebeccaMiyaji, TakamitsuMohammad, Faizan GoharMosser, BenoitMueller, Eva-MariaMuna, DemitriMuñoz-Gutiérrez, AndreaMyers, Adam D.Nadathur, SeshadriNair, PreethiNandra, Kirpaldo Nascimento, Janaina CorreaNevin, Rebecca JeanNewman, Jeffrey A.Nidever, David L.Nitschelm, ChristianNoterdaeme, PasquierO'Connell, Julia E.Olmstead, Matthew D.Oravetz, DanielOravetz, AudreyOsorio, YeissonPace, Zachary J.Padilla, NelsonPalanque-Delabrouille, NathaliePalicio, Pedro A.Pan, Hsi-AnPan, KaikeParker, JamesPaviot, RomainPeirani, SebastienPeña Ramŕez, KarlaPenny, SamanthaPercival, Will J.Perez-Fournon, IsmaelPérez-Ràfols, IgnasiPetitjean, PatrickPieri, Matthew M.Pinsonneault, MarcPoovelil, Vijith JacobPovick, Joshua TylerPrakash, AbhishekPrice-Whelan, Adrian M.Raddick, M. JordanRaichoor, AnandRay, AmyRembold, Sandro BarbozaRezaie, MehdiRiffel, Rogemar A.Riffel, RogérioRix, Hans-WalterRobin, Annie C.Roman-Lopes, A.Román-Zúñiga, CarlosRose, BenjaminRoss, Ashley J.Rossi, GrazianoRowlands, KateRubin, Kate H. R.Salvato, MaraSánchez, Ariel G.Sánchez-Menguiano, LauraSánchez-Gallego, José R.Sayres, ConorSchaefer, AdamSchiavon, Ricardo P.Schimoia, Jaderson S.Schlafly, EdwardSchlegel, DavidSchneider, Donald P.Schultheis, MathiasSchwope, AxelSeo, Hee-JongSerenelli, AldoShafieloo, ArmanShamsi, Shoaib JamalShao, ZhengyiShen, ShiyinShetrone, MatthewShirley, RaphaelSilva Aguirre, VíctorSimon, Joshua D.Skrutskie, M. F.Slosar, AnžeSmethurst, RebeccaSobeck, JenniferSodi, Bernardo CervantesSouto, DiogoStark, David V.Stassun, Keivan G.Steinmetz, MatthiasStello, DennisStermer, JuliannaStorchi-Bergmann, ThaisaStreblyanska, AlinaStringfellow, Guy S.Stutz, AmeliaSuárez, GenaroSun, JingTaghizadeh-Popp, ManuchehrTalbot, Michael S.Tayar, JamieThakar, Aniruddha R.Theriault, RileyThomas, DanielThomas, Zak C.Tinker, JeremyTojeiro, RitaToledo, Hector HernandezTremonti, Christy A.Troup, Nicholas W.Tuttle, SarahUnda-Sanzana, EduardoValentini, MaricaVargas-González, JaimeVargas-Magaña, MarianaVázquez-Mata, Jose AntonioVivek, M.Wake, DavidWang, YutingWeaver, Benjamin AlanWeijmans, Anne-MarieWild, VivienneWilson, John C.Wilson, Robert F.Wolthuis, NathanWood-Vasey, W. M.Yan, RenbinYang, MengYèche, ChristopheZamora, OlgaZarrouk, PaulineZasowski, GailZhang, KaiZhao, ChengZhao, GongboZheng, ZhengZhu, GuangtunZou, HuDOI: info:10.3847/1538-4365/ab929ev. 2493
Ahumada, Romina, Allende Prieto, Carlos, Almeida, Andrés, Anders, Friedrich, Anderson, Scott F., Andrews, Brett H., Anguiano, Borja, Arcodia, Riccardo, Armengaud, Eric, Aubert, Marie, Avila, Santiago, Avila-Reese, Vladimir, Badenes, Carles, Balland, Christophe, Barger, Kat, Barrera-Ballesteros, Jorge K., Basu, Sarbani, Bautista, Julian, Beaton, Rachael L., Beers, Timothy C., Benavides, B. Izamar T., Bender, Chad F., Bernardi, Mariangela, Bershady, Matthew, Beutler, Florian et al. 2020. "The 16th Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra." The Astrophysical Journal Supplement Series 249:3. https://doi.org/10.3847/1538-4365/ab929e
ID: 157795
Type: article
Authors: Ahumada, Romina; Allende Prieto, Carlos; Almeida, Andrés; Anders, Friedrich; Anderson, Scott F.; Andrews, Brett H.; Anguiano, Borja; Arcodia, Riccardo; Armengaud, Eric; Aubert, Marie; Avila, Santiago; Avila-Reese, Vladimir; Badenes, Carles; Balland, Christophe; Barger, Kat; Barrera-Ballesteros, Jorge K.; Basu, Sarbani; Bautista, Julian; Beaton, Rachael L.; Beers, Timothy C.; Benavides, B. Izamar T.; Bender, Chad F.; Bernardi, Mariangela; Bershady, Matthew; Beutler, Florian; Bidin, Christian Moni; Bird, Jonathan; Bizyaev, Dmitry; Blanc, Guillermo A.; Blanton, Michael R.; Boquien, Médéric; Borissova, Jura; Bovy, Jo; Brandt, W. N.; Brinkmann, Jonathan; Brownstein, Joel R.; Bundy, Kevin; Bureau, Martin; Burgasser, Adam; Burtin, Etienne; Cano-Díaz, Mariana; Capasso, Raffaella; Cappellari, Michele; Carrera, Ricardo; Chabanier, Solène; Chaplin, William; Chapman, Michael; Cherinka, Brian; Chiappini, Cristina; Doohyun Choi, Peter; Chojnowski, S. Drew; Chung, Haeun; Clerc, Nicolas; Coffey, Damien; Comerford, Julia M.; Comparat, Johan; da Costa, Luiz; Cousinou, Marie-Claude; Covey, Kevin; Crane, Jeffrey D.; Cunha, Katia; da Silva Ilha, Gabriele; Dai, Yu Sophia; Damsted, Sanna B.; Darling, Jeremy; Davidson, James W., Jr.; Davies, Roger; Dawson, Kyle; De, Nikhil; de la Macorra, Axel; De Lee, Nathan; de Andrade Queiroz, Anna Bárbara; Deconto Machado, Alice; de la Torre, Sylvain; Dell'Agli, Flavia; du Mas des Bourboux, Hélion; Diamond-Stanic, Aleksandar M.; Dillon, Sean; Donor, John; Drory, Niv; Duckworth, Chris; Dwelly, Tom; Ebelke, Garrett; Eftekharzadeh, Sarah; Eigenbrot, Arthur Davis; Elsworth, Yvonne P.; Eracleous, Mike; Erfanianfar, Ghazaleh; Escoffier, Stephanie; Fan, Xiaohui; Farr, Emily; Fernández-Trincado, José G.; Feuillet, Diane; Finoguenov, Alexis; Fofie, Patricia; Fraser-McKelvie, Amelia; Frinchaboy, Peter M.; Fromenteau, Sebastien; Fu, Hai; Galbany, Lluís; Garcia, Rafael A.; García-Hernández, D. A.; Garma Oehmichen, Luis Alberto; Ge, Junqiang; Geimba Maia, Marcio Antonio; Geisler, Doug; Gelfand, Joseph; Goddy, Julian; Gonzalez-Perez, Violeta; Grabowski, Kathleen; Green, Paul; Grier, Catherine J.; Guo, Hong; Guy, Julien; Harding, Paul; Hasselquist, Sten; Hawken, Adam James; Hayes, Christian R.; Hearty, Fred; Hekker, S.; Hogg, David W.; Holtzman, Jon A.; Horta, Danny; Hou, Jiamin; Hsieh, Bau-Ching; Huber, Daniel; Hunt, Jason A. S.; Ider Chitham, J.; Imig, Julie; Jaber, Mariana; Jimenez Angel, Camilo Eduardo; Johnson, Jennifer A.; Jones, Amy M.; Jönsson, Henrik; Jullo, Eric; Kim, Yerim; Kinemuchi, Karen; Kirkpatrick, Charles C.,IV; Kite, George W.; Klaene, Mark; Kneib, Jean-Paul; Kollmeier, Juna A.; Kong, Hui; Kounkel, Marina; Krishnarao, Dhanesh; Lacerna, Ivan; Lan, Ting-Wen; Lane, Richard R.; Law, David R.; Le Goff, Jean-Marc; Leung, Henry W.; Lewis, Hannah; Li, Cheng; Lian, Jianhui; Lin, Lihwai; Long, Dan; Longa-Peña, Penélope; Lundgren, Britt; Lyke, Brad W.; Ted Mackereth, J.; MacLeod, Chelsea L.; Majewski, Steven R.; Manchado, Arturo; Maraston, Claudia; Martini, Paul; Masseron, Thomas; Masters, Karen L.; Mathur, Savita; McDermid, Richard M.; Merloni, Andrea; Merrifield, Michael; Mészáros, Szabolcs; Miglio, Andrea; Minniti, Dante; Minsley, Rebecca; Miyaji, Takamitsu; Mohammad, Faizan Gohar; Mosser, Benoit; Mueller, Eva-Maria; Muna, Demitri; Muñoz-Gutiérrez, Andrea; Myers, Adam D.; Nadathur, Seshadri; Nair, Preethi; Nandra, Kirpal; do Nascimento, Janaina Correa; Nevin, Rebecca Jean; Newman, Jeffrey A.; Nidever, David L.; Nitschelm, Christian; Noterdaeme, Pasquier; O'Connell, Julia E.; Olmstead, Matthew D.; Oravetz, Daniel; Oravetz, Audrey; Osorio, Yeisson; Pace, Zachary J.; Padilla, Nelson; Palanque-Delabrouille, Nathalie; Palicio, Pedro A.; Pan, Hsi-An; Pan, Kaike; Parker, James; Paviot, Romain; Peirani, Sebastien; Peña Ramŕez, Karla; Penny, Samantha; Percival, Will J.; Perez-Fournon, Ismael; Pérez-Ràfols, Ignasi; Petitjean, Patrick; Pieri, Matthew M.; Pinsonneault, Marc; Poovelil, Vijith Jacob; Povick, Joshua Tyler; Prakash, Abhishek; Price-Whelan, Adrian M.; Raddick, M. Jordan; Raichoor, Anand; Ray, Amy; Rembold, Sandro Barboza; Rezaie, Mehdi; Riffel, Rogemar A.; Riffel, Rogério; Rix, Hans-Walter; Robin, Annie C.; Roman-Lopes, A.; Román-Zúñiga, Carlos; Rose, Benjamin; Ross, Ashley J.; Rossi, Graziano; Rowlands, Kate; Rubin, Kate H. R.; Salvato, Mara; Sánchez, Ariel G.; Sánchez-Menguiano, Laura; Sánchez-Gallego, José R.; Sayres, Conor; Schaefer, Adam; Schiavon, Ricardo P.; Schimoia, Jaderson S.; Schlafly, Edward; Schlegel, David; Schneider, Donald P.; Schultheis, Mathias; Schwope, Axel; Seo, Hee-Jong; Serenelli, Aldo; Shafieloo, Arman; Shamsi, Shoaib Jamal; Shao, Zhengyi; Shen, Shiyin; Shetrone, Matthew; Shirley, Raphael; Silva Aguirre, Víctor; Simon, Joshua D.; Skrutskie, M. F.; Slosar, Anže; Smethurst, Rebecca; Sobeck, Jennifer; Sodi, Bernardo Cervantes; Souto, Diogo; Stark, David V.; Stassun, Keivan G.; Steinmetz, Matthias; Stello, Dennis; Stermer, Julianna; Storchi-Bergmann, Thaisa; Streblyanska, Alina; Stringfellow, Guy S.; Stutz, Amelia; Suárez, Genaro; Sun, Jing; Taghizadeh-Popp, Manuchehr; Talbot, Michael S.; Tayar, Jamie; Thakar, Aniruddha R.; Theriault, Riley; Thomas, Daniel; Thomas, Zak C.; Tinker, Jeremy; Tojeiro, Rita; Toledo, Hector Hernandez; Tremonti, Christy A.; Troup, Nicholas W.; Tuttle, Sarah; Unda-Sanzana, Eduardo; Valentini, Marica; Vargas-González, Jaime; Vargas-Magaña, Mariana; Vázquez-Mata, Jose Antonio; Vivek, M.; Wake, David; Wang, Yuting; Weaver, Benjamin Alan; Weijmans, Anne-Marie; Wild, Vivienne; Wilson, John C.; Wilson, Robert F.; Wolthuis, Nathan; Wood-Vasey, W. M.; Yan, Renbin; Yang, Meng; Yèche, Christophe; Zamora, Olga; Zarrouk, Pauline; Zasowski, Gail; Zhang, Kai; Zhao, Cheng; Zhao, Gongbo; Zheng, Zheng; Zheng, Zheng; Zhu, Guangtun; Zou, Hu
Abstract: This paper documents the 16th data release (DR16) from the Sloan Digital Sky Surveys (SDSS), the fourth and penultimate from the fourth phase (SDSS-IV). This is the first release of data from the Southern Hemisphere survey of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2); new data from APOGEE-2 North are also included. DR16 is also notable as the final data release for the main cosmological program of the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), and all raw and reduced spectra from that project are released here. DR16 also includes all the data from the Time Domain Spectroscopic Survey and new data from the SPectroscopic IDentification of ERosita Survey programs, both of which were co-observed on eBOSS plates. DR16 has no new data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey (or the MaNGA Stellar Library "MaStar"). We also preview future SDSS-V operations (due to start in 2020), and summarize plans for the final SDSS-IV data release (DR17).
Herschel Observations of Disks around Late-type StarsTanner, AngellePlavchan, PeterBryden, GeoffKennedy, GrantMatrá, LucaCronin-Coltsmann, PatrickLowrance, PatrickHenry, ToddRiaz, BasmahGizis, John E.Riedel, AdricChoquet, ElodieDOI: info:10.1088/1538-3873/ab895fv. 132084401
Tanner, Angelle, Plavchan, Peter, Bryden, Geoff, Kennedy, Grant, Matrá, Luca, Cronin-Coltsmann, Patrick, Lowrance, Patrick, Henry, Todd, Riaz, Basmah, Gizis, John E., Riedel, Adric, and Choquet, Elodie. 2020. "Herschel Observations of Disks around Late-type Stars." Publications of the Astronomical Society of the Pacific 132:084401. https://doi.org/10.1088/1538-3873/ab895f
ID: 157796
Type: article
Authors: Tanner, Angelle; Plavchan, Peter; Bryden, Geoff; Kennedy, Grant; Matrá, Luca; Cronin-Coltsmann, Patrick; Lowrance, Patrick; Henry, Todd; Riaz, Basmah; Gizis, John E.; Riedel, Adric; Choquet, Elodie
Abstract: A set of twenty late-type (K5-M5) stars were observed with the Herschel Space Observatory at 100 and 160 microns with the goal of searching for far-infrared excesses indicative of the presence of circumstellar disks. Out of this sample, four stars (TYC 7443-1102-1, TYC 9340-437-1, GJ 784 and GJ 707) have infrared excesses above their stellar photospheres at either 100 or 160 μm or both. At 100 microns TYC 9340-437-1 is spatially resolved with a shape that suggests it is surrounded by a face-on disk. The 100 μm excess flux associated with GJ 707 is marginal at around 3σ. The excess flux associated with GJ 784 is most likely due to a background galaxy as the dust radius estimated from the spectral energy fit implies that any associated dust disk should have been resolved in the Herschel images but is not. TYC 7443-1102-1 has been observed with ALMA which resolves the emission at its location into two distinct sources making the Herschel excess most likely also due to a background galaxy. It is worth noting that this star is in the 23 Myr old β Pic association. With a disk luminosity on the order of 10-3 L*, this system is an ideal follow-up target for high-contrast imaging and ALMA.
Effects of self-consistent rest-ultraviolet colours in semi-empirical galaxy formation modelsMirocha, JordanMason, CharlotteStark, Daniel P.DOI: info:10.1093/mnras/staa2586v. 4982645–2661
Mirocha, Jordan, Mason, Charlotte, and Stark, Daniel P. 2020. "Effects of self-consistent rest-ultraviolet colours in semi-empirical galaxy formation models." Monthly Notices of the Royal Astronomical Society 498:2645– 2661. https://doi.org/10.1093/mnras/staa2586
ID: 157797
Type: article
Authors: Mirocha, Jordan; Mason, Charlotte; Stark, Daniel P.
Abstract: Connecting the observed rest-ultraviolet (UV) luminosities of high-z galaxies to their intrinsic luminosities (and thus star formation rates, SFRs) requires correcting for the presence of dust. We bypass a common dust-correction approach that uses empirical relationships between infrared (IR) emission and UV colours, and instead augment a semi-empirical model for galaxy formation with a simple - but self-consistent - dust model and use it to jointly fit high-z rest-UV luminosity functions (LFs) and colour-magnitude relations (MUV-β). In doing so, we find that UV colours evolve with redshift (at fixed UV magnitude), as suggested by observations, even in cases without underlying evolution in dust production, destruction, absorption, or geometry. The observed evolution in our model arises due to the reduction in the mean stellar age and rise in specific SFRs with increasing z. The UV extinction, AUV, evolves similarly with redshift, though we find a systematically shallower relation between AUV and MUV than that predicted by IRX-β relationships derived from z ∼ 3 galaxy samples. Finally, assuming that high $1600\hbox{-}{\mathring{\rm A}}$ transmission (≳0.6) is a reliable Ly α emitter (LAE) indicator, modest scatter in the effective dust surface density of galaxies can explain the evolution both in MUV-β and LAE fractions. These predictions are readily testable by deep surveys with the James Webb Space Telescope.
Spectroscopically Confirmed Lyα Emitters from Redshift 5 to 7 behind 10 Galaxy Cluster LensesFuller, S.Lemaux, B. C.Bradač, M.Hoag, A.Schmidt, K. B.Huang, K.Strait, V.Mason, Charlotte A.Treu, T.Pentericci, L.Trenti, M.Henry, A.Malkan, M.DOI: info:10.3847/1538-4357/ab959fv. 896156
Fuller, S., Lemaux, B. C., Bradač, M., Hoag, A., Schmidt, K. B., Huang, K., Strait, V., Mason, Charlotte A., Treu, T., Pentericci, L., Trenti, M., Henry, A., and Malkan, M. 2020. "Spectroscopically Confirmed Lyα Emitters from Redshift 5 to 7 behind 10 Galaxy Cluster Lenses." The Astrophysical Journal 896:156. https://doi.org/10.3847/1538-4357/ab959f
ID: 157798
Type: article
Authors: Fuller, S.; Lemaux, B. C.; Bradač, M.; Hoag, A.; Schmidt, K. B.; Huang, K.; Strait, V.; Mason, Charlotte A.; Treu, T.; Pentericci, L.; Trenti, M.; Henry, A.; Malkan, M.
Abstract: We present 36 spectroscopically confirmed intrinsically UV-faint Lyα-emitting galaxies from follow-up observations with Keck/DEep Imaging Multi-Object Spectrograph of gravitationally lensed high-redshift candidates. Candidates were selected to be between 5 ≲ z ≲ 7 from photometric data using Hubble Space Telescope and Spitzer imaging surveys. We performed an integrated photometric redshift probability cut >1% between 5 25 Å at 3σ at the fiducial depth of our survey, and only those galaxies with EW(Lyα) > 25 Å, and only objects with mAB < 26.8, we found the Lyα emitter (LAE) fraction to be flat or modestly increase from 0.26 ± 0.04 to 0.30 ± 0.04. These values are consistent with a rising LAE fraction with redshift out to z ∼ 6, but at z ∼ 6.5, there is some tension between our results and results from surveys at intrinsically brighter luminosities. We conclude that intrinsically fainter galaxies have Lyα emission, and there is a steep drop in the LAE fraction from our high-redshift sample at z ∼ 6.5 and from similar galaxies at z ∼ 7.5. This likely indicates we are witnessing the tail end of the epoch of reionization, as such a drop is not expected due to changes of intrinsic galaxy properties between these redshifts.
The Fornax Deep Survey with the VST. IV. A size and magnitude limited catalog of dwarf galaxies in the area of the Fornax cluster (Corrigendum)Venhola, AkuPeletier, ReynierLaurikainen, EijaSalo, HeikkiIodice, EnrichettaMieske, SteffenHilker, MichaelWittmann, CarolinLisker, ThorstenPaolillo, MaurizioCantiello, MicheleJanz, JoachimSpavone, MarilenaD'Abrusco, RaffaeleVen, GlennvandeNapolitano, NicolaKleijn, Gijs VerdoesMaddox, NatashaCapaccioli, MassimoGrado, AnielloValentijn, EdwinFalcón-Barroso, JesúsLimatola, LucaDOI: info:10.1051/0004-6361/201833933ev. 638C5
Venhola, Aku, Peletier, Reynier, Laurikainen, Eija, Salo, Heikki, Iodice, Enrichetta, Mieske, Steffen, Hilker, Michael, Wittmann, Carolin, Lisker, Thorsten, Paolillo, Maurizio, Cantiello, Michele, Janz, Joachim, Spavone, Marilena, D'Abrusco, Raffaele, Ven, Glennvande, Napolitano, Nicola, Kleijn, Gijs Verdoes, Maddox, Natasha, Capaccioli, Massimo, Grado, Aniello, Valentijn, Edwin, Falcón-Barroso, Jesús, and Limatola, Luca. 2020. "The Fornax Deep Survey with the VST. IV. A size and magnitude limited catalog of dwarf galaxies in the area of the Fornax cluster (Corrigendum)." Astronomy and Astrophysics 638:C5. https://doi.org/10.1051/0004-6361/201833933e
ID: 157799
Type: article
Authors: Venhola, Aku; Peletier, Reynier; Laurikainen, Eija; Salo, Heikki; Iodice, Enrichetta; Mieske, Steffen; Hilker, Michael; Wittmann, Carolin; Lisker, Thorsten; Paolillo, Maurizio; Cantiello, Michele; Janz, Joachim; Spavone, Marilena; D'Abrusco, Raffaele; Ven, Glennvande; Napolitano, Nicola; Kleijn, Gijs Verdoes; Maddox, Natasha; Capaccioli, Massimo; Grado, Aniello; Valentijn, Edwin; Falcón-Barroso, Jesús; Limatola, Luca
Abstract: This article is an erratum for:[https://doi.org/10.1051/0004-6361/201833933]
The Fornax Deep Survey with VST. IX. Catalog of sources in the FDS area with an example study for globular clusters and background galaxiesCantiello, MicheleVenhola, AkuGrado, AnielloPaolillo, MaurizioD'Abrusco, RaffaeleRaimondo, GabriellaQuintini, MassimoHilker, MichaelMieske, SteffenTortora, CrescenzoSpavone, MarilenaCapaccioli, MassimoIodice, EnricaPeletier, ReynierBarroso, Jesús FalcónLimatola, LucaNapolitano, NicolaSchipani, Pietrovan de Ven, GlennGentile, FabrizioCovone, GiovanniDOI: info:10.1051/0004-6361/202038137v. 639A136
Cantiello, Michele, Venhola, Aku, Grado, Aniello, Paolillo, Maurizio, D'Abrusco, Raffaele, Raimondo, Gabriella, Quintini, Massimo, Hilker, Michael, Mieske, Steffen, Tortora, Crescenzo, Spavone, Marilena, Capaccioli, Massimo, Iodice, Enrica, Peletier, Reynier, Barroso, Jesús Falcón, Limatola, Luca, Napolitano, Nicola, Schipani, Pietro, van de Ven, Glenn, Gentile, Fabrizio, and Covone, Giovanni. 2020. "The Fornax Deep Survey with VST. IX. Catalog of sources in the FDS area with an example study for globular clusters and background galaxies." Astronomy and Astrophysics 639:A136. https://doi.org/10.1051/0004-6361/202038137
ID: 157800
Type: article
Authors: Cantiello, Michele; Venhola, Aku; Grado, Aniello; Paolillo, Maurizio; D'Abrusco, Raffaele; Raimondo, Gabriella; Quintini, Massimo; Hilker, Michael; Mieske, Steffen; Tortora, Crescenzo; Spavone, Marilena; Capaccioli, Massimo; Iodice, Enrica; Peletier, Reynier; Barroso, Jesús Falcón; Limatola, Luca; Napolitano, Nicola; Schipani, Pietro; van de Ven, Glenn; Gentile, Fabrizio; Covone, Giovanni
Abstract: Context. A possible pathway for understanding the events and the mechanisms involved in galaxy formation and evolution is an in-depth investigation of the galactic and inter-galactic fossil sub-structures with long dynamical timescales: stars in the field and in stellar clusters.
Aims: This paper continues the Fornax Deep Survey (FDS) series. Following previous studies dedicated to extended Fornax cluster members, we present the catalogs of compact stellar systems in the Fornax cluster, as well as extended background sources and point-like sources.
Methods: We derived ugri photometry of ∼1.7 million sources over the ∼21 square degree area of FDS centered on the bright central galaxy NGC 1399. For a wider area, of ∼27 square degrees extending in the direction of NGC 1316, we provided gri photometry for ∼3.1 million sources. To improve the morphological characterization of sources, we generated multi-band image stacks by coadding the best-seeing gri-band single exposures with a cut at full width at half maximum (FWHM) ≤ 0.″9. We used the multi-band stacks as master detection frames, with a FWHM improved by ∼15% and a FWHM variability from field to field reduced by a factor of ∼2.5 compared to the pass-band with the best FWHM, namely the r-band. The identification of compact sources, in particular, globular clusters (GC), was obtained from a combination of photometric (e.g., colors, magnitudes) and morphometric (e.g., concentration index, elongation, effective radius) selection criteria, also taking as reference the properties of sources with well-defined classifications from spectroscopic or high-resolution imaging data.
Results: Using the FDS catalogs, we present a preliminary analysis of GC distributions in the Fornax area. The study confirms and extends further previous results that were limited to a smaller survey area. We observed the inter-galactic population of GCs, a population of mainly blue GCs centered on NGC 1399, extending over ∼0.9 Mpc, with an ellipticity ∊ ∼ 0.65 and a small tilt in the direction of NGC 1336. Several sub-structures extend over ∼0.5 Mpc along various directions. Two of these structures do not cross any bright galaxy; one of them appears to be connected to NGC 1404, a bright galaxy close to the cluster core and particularly poor in GCs. Using the gri catalogs, we analyze the GC distribution over the extended FDS area and do not find any obvious GC sub-structure bridging the two brightest cluster galaxies, namely, NGC 1316 and NGC 1399. Although NGC 1316 is more than twice as bright of NGC 1399 in optical bands, using gri data, we estimate a GC population that is richer by a factor of ∼3-4 around NGC 1399, as compared to NGC 1316, out to galactocentric distances of ∼40' or ∼230 kpc.
Full Tables 3-6 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/639/A136
On the Physical Association of Fermi-LAT Blazars with Their Low-energy Counterpartsde Menezes, RaniereD'Abrusco, RaffaeleMassaro, FrancescoGasparrini, DarioNemmen, RodrigoDOI: info:10.3847/1538-4365/ab8c4ev. 24823
de Menezes, Raniere, D'Abrusco, Raffaele, Massaro, Francesco, Gasparrini, Dario, and Nemmen, Rodrigo. 2020. "On the Physical Association of Fermi-LAT Blazars with Their Low-energy Counterparts." The Astrophysical Journal Supplement Series 248:23. https://doi.org/10.3847/1538-4365/ab8c4e
ID: 157801
Type: article
Authors: de Menezes, Raniere; D'Abrusco, Raffaele; Massaro, Francesco; Gasparrini, Dario; Nemmen, Rodrigo
Abstract: Associating γ-ray sources to their low-energy counterparts is one of the major challenges of modern γ-ray astronomy. In the context of the Fourth Fermi Large Area Telescope Source Catalog (4FGL), the associations rely mainly on parameters such as apparent magnitude, integrated flux, and angular separation between the γ-ray source and its low-energy candidate counterpart. In this work, we propose a new use of the likelihood ratio (LR) and a complementary supervised learning technique to associate γ-ray blazars in 4FGL, based only on spectral parameters such as the γ-ray photon index, mid-infrared colors, and radio-loudness. In the LR approach, we crossmatch the Wide-field Infrared Survey Explorer Blazar-Like Radio-Loud Sources catalog with 4FGL and compare the resulting candidate counterparts with the sources listed in the γ-ray blazar locus to compute an association probability (AP) for 1138 counterparts. In the supervised learning approach, we train a random forest algorithm with 869 high-confidence blazar associations and 711 fake associations and then compute an AP for 1311 candidate counterparts. A list with all 4FGL blazar candidates of uncertain type associated by our method is provided to guide future optical spectroscopic follow-up observations.
Synthetic catalog of black holes in the Milky WayOlejak, A.Belczynski, K.Bulik, T.Sobolewska, MalgosiaDOI: info:10.1051/0004-6361/201936557v. 638A94
Olejak, A., Belczynski, K., Bulik, T., and Sobolewska, Malgosia. 2020. "Synthetic catalog of black holes in the Milky Way." Astronomy and Astrophysics 638:A94. https://doi.org/10.1051/0004-6361/201936557
ID: 157802
Type: article
Authors: Olejak, A.; Belczynski, K.; Bulik, T.; Sobolewska, Malgosia
Abstract: Aims: We present an open-access database that includes a synthetic catalog of black holes (BHs) in the Milky Way, divided by the components disk, bulge, and halo. Methods: To calculate the evolution of single and binary stars, we used the updated population synthesis code StarTrack. We applied a new model of the star formation history and chemical evolution of Galactic disk, bulge, and halo that was synthesized from observational and theoretical data. This model can be easily employed for other studies of population evolution. Results: We find that at the current Milky Way (disk+bulge+halo) contains about 1.2 × 108 single BHs with an average mass of about 14 M, and 9.3 × 106 BHs in binary systems with an average mass of 19 M. We present basic statistical properties of the BH population in three Galactic components such as the distributions of BH masses, velocities, or the numbers of BH binary systems in different evolutionary configurations. Conclusions: The metallicity of a stellar population has a significant effect on the final BH mass through the stellar winds. The most massive single BH in our simulation of 113 M originates from a merger of a BH and a helium star in a low-metallicity stellar environment in the Galactic halo. We constrain that only ∼0.006% of the total Galactic halo mass (including dark matter) can be hidden in the form of stellar origin BHs. These BHs cannot be detected by current observational surveys. We calculated the merger rates for current Galactic double compact objects (DCOs) for two considered common-envelope models: ∼3-81 Myr-1 for BH-BH, ∼1-9 Myr-1 for BH-neutron star (NS), and ∼14-59 Myr-1 for NS-NS systems. We show the evolution of the merger rates of DCOs since the formation of the Milky Way until the current moment with the new star formation model of the Galaxy. Data files are available on our website, http://https://bhc.syntheticuniverse.org/.
Star-Gas Surface Density Correlations in 12 Nearby Molecular Clouds. I. Data Collection and Star-sampled AnalysisPokhrel, RiwajGutermuth, Robert A.Betti, Sarah K.Offner, Stella S. R.Myers, Philip C.Megeath, S. ThomasSokol, Alyssa D.Ali, BabarAllen, LoriAllen, Thomas S.Dunham, Michael M.Fischer, William J.Henning, ThomasHeyer, MarkHora, Joseph L.Pipher, Judith L.Tobin, John J.Wolk, Scott J.DOI: info:10.3847/1538-4357/ab92a2v. 89660
Pokhrel, Riwaj, Gutermuth, Robert A., Betti, Sarah K., Offner, Stella S. R., Myers, Philip C., Megeath, S. Thomas, Sokol, Alyssa D., Ali, Babar, Allen, Lori, Allen, Thomas S., Dunham, Michael M., Fischer, William J., Henning, Thomas, Heyer, Mark, Hora, Joseph L., Pipher, Judith L., Tobin, John J., and Wolk, Scott J. 2020. "Star-Gas Surface Density Correlations in 12 Nearby Molecular Clouds. I. Data Collection and Star-sampled Analysis." The Astrophysical Journal 896:60. https://doi.org/10.3847/1538-4357/ab92a2
ID: 157803
Type: article
Authors: Pokhrel, Riwaj; Gutermuth, Robert A.; Betti, Sarah K.; Offner, Stella S. R.; Myers, Philip C.; Megeath, S. Thomas; Sokol, Alyssa D.; Ali, Babar; Allen, Lori; Allen, Thomas S.; Dunham, Michael M.; Fischer, William J.; Henning, Thomas; Heyer, Mark; Hora, Joseph L.; Pipher, Judith L.; Tobin, John J.; Wolk, Scott J.
Abstract: We explore the relation between the stellar mass surface density and the mass surface density of molecular hydrogen gas in 12 nearby molecular clouds that are located at <1.5 kpc distance. The sample clouds span an order-of-magnitude range in mass, size, and star formation rates. We use thermal dust emission from Herschel maps to probe the gas surface density and the young stellar objects from the most recent Spitzer Extended Solar Neighborhood Archive catalog to probe the stellar surface density. Using a star-sampled nearest neighbor technique to probe the star-gas surface density correlations at the scale of a few parsecs, we find that the stellar mass surface density varies as a power law of the gas mass surface density, with a power-law index of ∼2 in all the clouds. The consistent power-law index implies that star formation efficiency is directly correlated with gas column density, and no gas column density threshold for star formation is observed. We compare the observed correlations with the predictions from an analytical model of thermal fragmentation and with the synthetic observations of a recent hydrodynamic simulation of a turbulent star-forming molecular cloud. We find that the observed correlations are consistent for some clouds with the thermal fragmentation model and can be reproduced using the hydrodynamic simulations.
A Census of Star Formation in the Outer Galaxy. II. The GLIMPSE360 FieldWinston, ElaineHora, Joseph L.Tolls, VolkerDOI: info:10.3847/1538-3881/ab99c8v. 16068
Winston, Elaine, Hora, Joseph L., and Tolls, Volker. 2020. "A Census of Star Formation in the Outer Galaxy. II. The GLIMPSE360 Field." The Astronomical Journal 160:68. https://doi.org/10.3847/1538-3881/ab99c8
ID: 157804
Type: article
Authors: Winston, Elaine; Hora, Joseph L.; Tolls, Volker
Abstract: We have conducted a study of star formation in the outer Galaxy from 65°180° in Galactic longitude. Using the DBSCAN method on the combined catalog, we identify 618 clusters or aggregations of YSOs having five or more members. We identify 10,476 class I, 29,604 class II, and 7325 anemic class II/class III YSOs. The ratio of YSOs identified as members of clusters was 25,528/47,338, or 54%. We found that 100 of the clusters identified have previously measured distances in the WISE H II survey. We used these distances in our spectral energy distribution (SED) fitting of the YSOs in these clusters, of which 96 had YSOs with 180° in Galactic longitude. Using the DBSCAN method on the combined catalog, we identify 618 clusters or aggregations of YSOs having five or more members. We identify 10,476 class I, 29,604 class II, and 7325 anemic class II/class III YSOs. The ratio of YSOs identified as members of clusters was 25,528/47,338, or 54%. We found that 100 of the clusters identified have previously measured distances in the WISE H II survey. We used these distances in our spectral energy distribution (SED) fitting of the YSOs in these clusters, of which 96 had YSOs with for RGal for RGal > 11.5 kpc. The slope of the combined IMF was found to be Γ = 1.92 ± 0.42 above 3 M. These values are consistent with each other within the uncertainties and with literature values in the inner Galaxy high-mass star formation regions. The slopes are likely also consistent with a universal Salpeter IMF.
CMZoom: Survey Overview and First Data ReleaseBattersby, CaraKeto, EricWalker, DanielBarnes, AshleyCallanan, DanielGinsburg, AdamHatchfield, H. PerryHenshaw, JonathanKauffmann, JensKruijssen, J. M. DiederikLongmore, Steven N.Lu, XingMills, Elisabeth A. C.Pillai, ThusharaZhang, QizhouBally, JohnButterfield, NatalieContreras, Yanett A.Ho, Luis C.Ott, JürgenPatel, NimeshTolls, VolkerDOI: info:10.3847/1538-4365/aba18ev. 24935
Battersby, Cara, Keto, Eric, Walker, Daniel, Barnes, Ashley, Callanan, Daniel, Ginsburg, Adam, Hatchfield, H. Perry, Henshaw, Jonathan, Kauffmann, Jens, Kruijssen, J. M. Diederik, Longmore, Steven N., Lu, Xing, Mills, Elisabeth A. C., Pillai, Thushara, Zhang, Qizhou, Bally, John, Butterfield, Natalie, Contreras, Yanett A., Ho, Luis C., Ott, Jürgen, Patel, Nimesh, and Tolls, Volker. 2020. "CMZoom: Survey Overview and First Data Release." The Astrophysical Journal Supplement Series 249:35. https://doi.org/10.3847/1538-4365/aba18e
ID: 157805
Type: article
Authors: Battersby, Cara; Keto, Eric; Walker, Daniel; Barnes, Ashley; Callanan, Daniel; Ginsburg, Adam; Hatchfield, H. Perry; Henshaw, Jonathan; Kauffmann, Jens; Kruijssen, J. M. Diederik; Longmore, Steven N.; Lu, Xing; Mills, Elisabeth A. C.; Pillai, Thushara; Zhang, Qizhou; Bally, John; Butterfield, Natalie; Contreras, Yanett A.; Ho, Luis C.; Ott, Jürgen; Patel, Nimesh; Tolls, Volker
Abstract: We present an overview of the CMZoom survey and its first data release. CMZoom is the first blind, high-resolution survey of the Central Molecular Zone (CMZ; the inner 500 pc of the Milky Way) at wavelengths sensitive to the pre-cursors of high-mass stars. CMZoom is a 550 hr Large Program on the Submillimeter Array that mapped at 1.3 mm all of the gas and dust in the CMZ above a molecular hydrogen column density of 1023 cm-2 at a resolution of ∼3″ (0.1 pc). In this paper, we focus on the 1.3 mm dust continuum and its data release, but also describe CMZoom spectral line data which will be released in a forthcoming publication. While CMZoom detected many regions with rich and complex substructure, its key result is an overall deficit in compact substructures on 0.1-2 pc scales (the compact dense gas fraction: CDGF). In comparison with clouds in the Galactic disk, the CDGF in the CMZ is substantially lower, despite having much higher average column densities. CMZ clouds with high CDGFs are well-known sites of active star formation. The inability of most gas in the CMZ to form compact substructures is likely responsible for the dearth of star formation in the CMZ, surprising considering its high density. The factors responsible for the low CDGF are not yet understood but are plausibly due to the extreme environment of the CMZ, having far-reaching ramifications for our understanding of the star formation process across the cosmos.
STRIDES: Spectroscopic and photometric characterization of the environment and effects of mass along the line of sight to the gravitational lenses DES J0408-5354 and WGD 2038-4008Buckley-Geer, E. J.Lin, H.Rusu, C. E.Poh, J.Palmese, A.Agnello, A.Christensen, L.Frieman, J.Shajib, A. J.Treu, T.Collett, T.Birrer, S.Anguita, T.Fassnacht, C. D.Meylan, G.Mukherjee, S.Wong, K. C.Aguena, M.Allam, S.Avila, S.Bertin, E.Bhargava, S.Brooks, D.Carnero Rosell, A.Carrasco Kind, M.Carretero, J.Castander, F. J.Costanzi, M.da Costa, L. N.De Vicente, J.Desai, S.Diehl, H. T.Doel, P.Eifler, T. F.Everett, S.Flaugher, B.Fosalba, P.García-Bellido, J.Gaztanaga, E.Gruen, D.Gruendl, R. A.Gschwend, J.Gutierrez, G.Hinton, S. R.Honscheid, K.James, David J.Kuehn, K.Kuropatkin, N.Maia, M. A. G.Marshall, J. L.Melchior, P.Menanteau, F.Miquel, R.Ogando, R. L. C.Paz-Chinchón, F.Plazas, A. A.Sanchez, E.Scarpine, V.Schubnell, M.Serrano, S.Sevilla-Noarbe, I.Smith, M.Soares-Santos, M.Suchyta, E.Swanson, M. E. C.Tarle, G.Tucker, D. L.Varga, T. N.DES CollaborationDOI: info:10.1093/mnras/staa2563v. 4983241–3274
Buckley-Geer, E. J., Lin, H., Rusu, C. E., Poh, J., Palmese, A., Agnello, A., Christensen, L., Frieman, J., Shajib, A. J., Treu, T., Collett, T., Birrer, S., Anguita, T., Fassnacht, C. D., Meylan, G., Mukherjee, S., Wong, K. C., Aguena, M., Allam, S., Avila, S., Bertin, E., Bhargava, S., Brooks, D., Carnero Rosell, A., Carrasco Kind, M. et al. 2020. "STRIDES: Spectroscopic and photometric characterization of the environment and effects of mass along the line of sight to the gravitational lenses DES J0408-5354 and WGD 2038-4008." Monthly Notices of the Royal Astronomical Society 498:3241– 3274. https://doi.org/10.1093/mnras/staa2563
ID: 157806
Type: article
Authors: Buckley-Geer, E. J.; Lin, H.; Rusu, C. E.; Poh, J.; Palmese, A.; Agnello, A.; Christensen, L.; Frieman, J.; Shajib, A. J.; Treu, T.; Collett, T.; Birrer, S.; Anguita, T.; Fassnacht, C. D.; Meylan, G.; Mukherjee, S.; Wong, K. C.; Aguena, M.; Allam, S.; Avila, S.; Bertin, E.; Bhargava, S.; Brooks, D.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Castander, F. J.; Costanzi, M.; da Costa, L. N.; De Vicente, J.; Desai, S.; Diehl, H. T.; Doel, P.; Eifler, T. F.; Everett, S.; Flaugher, B.; Fosalba, P.; García-Bellido, J.; Gaztanaga, E.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Hinton, S. R.; Honscheid, K.; James, David J.; Kuehn, K.; Kuropatkin, N.; Maia, M. A. G.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Miquel, R.; Ogando, R. L. C.; Paz-Chinchón, F.; Plazas, A. A.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Serrano, S.; Sevilla-Noarbe, I.; Smith, M.; Soares-Santos, M.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Tucker, D. L.; Varga, T. N.; DES Collaboration
Abstract: In time-delay cosmography, three of the key ingredients are (1) determining the velocity dispersion of the lensing galaxy, (2) identifying galaxies and groups along the line of sight with sufficient proximity and mass to be included in the mass model, and (3) estimating the external convergence κext from less massive structures that are not included in the mass model. We present results on all three of these ingredients for two time-delay lensed quad quasar systems, DES J0408-5354 and WGD 2038-4008 . We use the Gemini, Magellan, and VLT telescopes to obtain spectra to both measure the stellar velocity dispersions of the main lensing galaxies and to identify the line-of-sight galaxies in these systems. Next, we identify 10 groups in DES J0408-5354 and two groups in WGD 2038-4008 using a group-finding algorithm. We then identify the most significant galaxy and galaxy-group perturbers using the 'flexion shift' criterion. We determine the probability distribution function of the external convergence κext for both of these systems based on our spectroscopy and on the DES-only multiband wide-field observations. Using weighted galaxy counts, calibrated based on the Millennium Simulation, we find that DES J0408-5354 is located in a significantly underdense environment, leading to a tight (width $\sim 3{{\ \rm per\ cent}}$ ), negative-value κext distribution. On the other hand, WGD 2038-4008 is located in an environment of close to unit density, and its low source redshift results in a much tighter κext of $\sim 1{{\ \rm per\ cent}}$ , as long as no external shear constraints are imposed.
The TOI-763 system: sub-Neptunes orbiting a Sun-like starFridlund, M.Livingston, J.Gandolfi, D.Persson, C. M.Lam, K. W. F.Stassun, K. G.Hellier, C.Korth, J.Hatzes, A. P.Malavolta, L.Luque, R.Redfield, S.Guenther, E. W.Albrecht, S.Barragan, O.Benatti, S.Bouma, L.Cabrera, J.Cochran, W. D.Csizmadia, S.Dai, F.Deeg, H. J.Esposito, M.Georgieva, I.Grziwa, S.González Cuesta, L.Hirano, T.Jenkins, J. M.Kabath, P.Knudstrup, E.Latham, David W.Mathur, S.Mullally, S. E.Narita, N.Nowak, G.Olofsson, A. O. H.Palle, E.Pätzold, M.Pompei, E.Rauer, H.Ricker, G.Rodler, F.Seager, S.Serrano, L. M.Smith, A. M. S.Spina, L.Subjak, J.Tenenbaum, P.Ting, E. B.Vanderburg, A.Vanderspek, R.Van Eylen, V.Villanueva, S.Winn, J. N.DOI: info:10.1093/mnras/staa2502v. 4984503–4517
Fridlund, M., Livingston, J., Gandolfi, D., Persson, C. M., Lam, K. W. F., Stassun, K. G., Hellier, C., Korth, J., Hatzes, A. P., Malavolta, L., Luque, R., Redfield, S., Guenther, E. W., Albrecht, S., Barragan, O., Benatti, S., Bouma, L., Cabrera, J., Cochran, W. D., Csizmadia, S., Dai, F., Deeg, H. J., Esposito, M., Georgieva, I., Grziwa, S. et al. 2020. "The TOI-763 system: sub-Neptunes orbiting a Sun-like star." Monthly Notices of the Royal Astronomical Society 498:4503– 4517. https://doi.org/10.1093/mnras/staa2502
ID: 157807
Type: article
Authors: Fridlund, M.; Livingston, J.; Gandolfi, D.; Persson, C. M.; Lam, K. W. F.; Stassun, K. G.; Hellier, C.; Korth, J.; Hatzes, A. P.; Malavolta, L.; Luque, R.; Redfield, S.; Guenther, E. W.; Albrecht, S.; Barragan, O.; Benatti, S.; Bouma, L.; Cabrera, J.; Cochran, W. D.; Csizmadia, S.; Dai, F.; Deeg, H. J.; Esposito, M.; Georgieva, I.; Grziwa, S.; González Cuesta, L.; Hirano, T.; Jenkins, J. M.; Kabath, P.; Knudstrup, E.; Latham, David W.; Mathur, S.; Mullally, S. E.; Narita, N.; Nowak, G.; Olofsson, A. O. H.; Palle, E.; Pätzold, M.; Pompei, E.; Rauer, H.; Ricker, G.; Rodler, F.; Seager, S.; Serrano, L. M.; Smith, A. M. S.; Spina, L.; Subjak, J.; Tenenbaum, P.; Ting, E. B.; Vanderburg, A.; Vanderspek, R.; Van Eylen, V.; Villanueva, S.; Winn, J. N.
Abstract: We report the discovery of a planetary system orbiting TOI-763(aka CD-39 7945), a V = 10.2, high proper motion G-type dwarf star that was photometrically monitored by the TESS space mission in Sector 10. We obtain and model the stellar spectrum and find an object slightly smaller than the Sun, and somewhat older, but with a similar metallicity. Two planet candidates were found in the light curve to be transiting the star. Combining TESS transit photometry with HARPS high-precision radial velocity (RV) follow-up measurements confirm the planetary nature of these transit signals. We determine masses, radii, and bulk densities of these two planets. A third planet candidate was discovered serendipitously in the RV data. The inner transiting planet, TOI-763 b, has an orbital period of Pb = 5.6 d, a mass of Mb = 9.8 ± 0.8 M, and a radius of Rb = 2.37 ± 0.10 R. The second transiting planet, TOI-763 c, has an orbital period of Pc = 12.3 d, a mass of Mc = 9.3 ± 1.0 M, and a radius of Rc = 2.87 ± 0.11 R. We find the outermost planet candidate to orbit the star with a period of ∼48 d. If confirmed as a planet, it would have a minimum mass of Md = 9.5 ± 1.6 M. We investigated the TESS light curve in order to search for a mono transit by planet d without success. We discuss the importance and implications of this planetary system in terms of the geometrical arrangements of planets orbiting G-type stars.
Powerful ionized gas outflows in the interacting radio galaxy 4C+29.30Couto, Guilherme S.Storchi-Bergmann, ThaisaSiemiginowska, AnetaRiffel, Rogemar A.Morganti, RaffaellaDOI: info:10.1093/mnras/staa2268v. 4975103–5117
Couto, Guilherme S., Storchi-Bergmann, Thaisa, Siemiginowska, Aneta, Riffel, Rogemar A., and Morganti, Raffaella. 2020. "Powerful ionized gas outflows in the interacting radio galaxy 4C+29.30." Monthly Notices of the Royal Astronomical Society 497:5103– 5117. https://doi.org/10.1093/mnras/staa2268
ID: 157808
Type: article
Authors: Couto, Guilherme S.; Storchi-Bergmann, Thaisa; Siemiginowska, Aneta; Riffel, Rogemar A.; Morganti, Raffaella
Abstract: We investigate the ionized gas excitation and kinematics in the inner $4.3\, \times \, 6.2$ kpc2 of the merger radio galaxy 4C+29.30. Using optical integral field spectroscopy with the Gemini North Telescope, we present flux distributions, line-ratio maps, peak velocities and velocity dispersion maps as well as channel maps with a spatial resolution of $\approx\! 955\,$ pc. We observe high blueshifts of up to $\sim\! -650\,$$\rm km\, s^{-1}$ in a region ∼1 arcsec south of the nucleus (the southern knot - SK), which also presents high velocity dispersions ($\sim\! 250\,$$\rm km\, s^{-1}$), which we attribute to an outflow. A possible redshifted counterpart is observed north from the nucleus (the northern knot - NK). We propose that these regions correspond to a bipolar outflow possibly due to the interaction of the radio jet with the ambient gas. We estimate a total ionized gas mass outflow rate of $\dot{M}_{\mathrm{ out}} = 25.4 ^{+11.5 }_{ -7.5}\,$ M yr-1with a kinetic power of $\dot{E} = 8.1 ^{+10.7 }_{ -4.0} \times 10^{42}\,$ erg s-1, which represents $5.8 ^{+7.6 }_{ -2.9} {{\ \rm per\ cent}}$ of the active galactic nucleus (AGN) bolometric luminosity. These values are higher than usually observed in nearby active galaxies with the same bolometric luminosities and could imply a significant impact of the outflows in the evolution of the host galaxy. The excitation is higher in the NK - that correlates with extended X-ray emission, indicating the presence of hotter gas - than in the SK, supporting a scenario in which an obscuring dust lane is blocking part of the AGN radiation to reach the southern region of the galaxy.
Resonant Dipolar Collisions of Ultracold Molecules Induced by Microwave DressingYan, Zoe Z.Park, Jee WooNi, YiqiLoh, HuanqianWill, SebastianKarman, TijsZwierlein, MartinDOI: info:10.1103/PhysRevLett.125.063401v. 125063401
Yan, Zoe Z., Park, Jee Woo, Ni, Yiqi, Loh, Huanqian, Will, Sebastian, Karman, Tijs, and Zwierlein, Martin. 2020. "Resonant Dipolar Collisions of Ultracold Molecules Induced by Microwave Dressing." Physical Review Letters 125:063401. https://doi.org/10.1103/PhysRevLett.125.063401
ID: 157809
Type: article
Authors: Yan, Zoe Z.; Park, Jee Woo; Ni, Yiqi; Loh, Huanqian; Will, Sebastian; Karman, Tijs; Zwierlein, Martin
Abstract: We demonstrate microwave dressing on ultracold, fermionic 23Na 40K ground-state molecules and observe resonant dipolar collisions with cross sections exceeding 3 times the s -wave unitarity limit. The origin of these interactions is the resonant alignment of the approaching molecules' dipoles along the intermolecular axis, which leads to strong attraction. We explain our observations with a conceptually simple two-state picture based on the Condon approximation. Furthermore, we perform coupled-channel calculations that agree well with the experimentally observed collision rates. The resonant microwave-induced collisions found here enable controlled, strong interactions between molecules, of immediate use for experiments in optical lattices.
LRG-BEASTS: ground-based detection of sodium and a steep optical slope in the atmosphere of the highly inflated hot-saturn WASP-21bAlderson, L.Kirk, JamesLópez-Morales, MercedesWheatley, P. J.Skillen, I.Henry, G. W.McGruder, ChimaBrogi, M.Louden, T.King, G.DOI: info:10.1093/mnras/staa2315v. 4975182–5202
Alderson, L., Kirk, James, López-Morales, Mercedes, Wheatley, P. J., Skillen, I., Henry, G. W., McGruder, Chima, Brogi, M., Louden, T., and King, G. 2020. "LRG-BEASTS: ground-based detection of sodium and a steep optical slope in the atmosphere of the highly inflated hot-saturn WASP-21b." Monthly Notices of the Royal Astronomical Society 497:5182– 5202. https://doi.org/10.1093/mnras/staa2315
ID: 157810
Type: article
Authors: Alderson, L.; Kirk, James; López-Morales, Mercedes; Wheatley, P. J.; Skillen, I.; Henry, G. W.; McGruder, Chima; Brogi, M.; Louden, T.; King, G.
Abstract: We present the optical transmission spectrum of the highly inflated Saturn-mass exoplanet WASP-21b, using three transits obtained with the ACAM instrument on the William Herschel Telescope through the LRG-BEASTS survey (Low Resolution Ground-Based Exoplanet Atmosphere Survey using Transmission Spectroscopy). Our transmission spectrum covers a wavelength range of 4635-9000 Å, achieving an average transit depth precision of 197 ppm compared to one atmospheric scale height at 246 ppm. We detect Na I absorption in a bin width of 30 Å at >4σ confidence, which extends over 100 Å. We see no evidence of absorption from K I. Atmospheric retrieval analysis of the scattering slope indicates it is too steep for Rayleigh scattering from H2, but is very similar to that of HD 189733b. The features observed in our transmission spectrum cannot be caused by stellar activity alone, with photometric monitoring of WASP-21 showing it to be an inactive star. We therefore conclude that aerosols in the atmosphere of WASP-21b are giving rise to the steep slope that we observe, and that WASP-21b is an excellent target for infrared observations to constrain its atmospheric metallicity.
Validation of selection function, sample contamination and mass calibration in galaxy cluster samplesGrandis, S.Klein, M.Mohr, J. J.Bocquet, S.Paulus, M.Abbott, T. M. C.Aguena, M.Allam, S.Annis, J.Benson, B. A.Bertin, E.Bhargava, S.Brooks, D.Burke, D. L.Carnero Rosell, A.Carrasco Kind, M.Carretero, J.Capasso, R.Costanzi, M.da Costa, L. N.De Vicente, J.Desai, S.Dietrich, J. P.Doel, P.Eifler, T. F.Evrard, A. E.Flaugher, B.Fosalba, P.Frieman, J.García-Bellido, J.Gaztanaga, E.Gerdes, D. W.Gruen, D.Gruendl, R. A.Gschwend, J.Gutierrez, G.Hartley, W. G.Hinton, S. R.Hollowood, D. L.Honscheid, K.James, David J.Jeltema, T.Kuehn, K.Kuropatkin, N.Lima, M.Maia, M. A. G.Marshall, J. L.Melchior, P.Menanteau, F.Miquel, R.Ogando, R. L. C.Palmese, A.Paz-Chinchón, F.Plazas, A. A.Romer, A. K.Roodman, A.Sanchez, E.Saro, A.Scarpine, V.Schubnell, M.Serrano, S.Sheldon, E.Smith, M.Stark, Antony A.Suchyta, E.Swanson, M. E. C.Tarle, G.Thomas, D.Tucker, D. L.Varga, T. N.Weller, J.Wilkinson, R.DOI: info:10.1093/mnras/staa2333v. 498771–798
Grandis, S., Klein, M., Mohr, J. J., Bocquet, S., Paulus, M., Abbott, T. M. C., Aguena, M., Allam, S., Annis, J., Benson, B. A., Bertin, E., Bhargava, S., Brooks, D., Burke, D. L., Carnero Rosell, A., Carrasco Kind, M., Carretero, J., Capasso, R., Costanzi, M., da Costa, L. N., De Vicente, J., Desai, S., Dietrich, J. P., Doel, P., Eifler, T. F. et al. 2020. "Validation of selection function, sample contamination and mass calibration in galaxy cluster samples." Monthly Notices of the Royal Astronomical Society 498:771– 798. https://doi.org/10.1093/mnras/staa2333
ID: 157811
Type: article
Authors: Grandis, S.; Klein, M.; Mohr, J. J.; Bocquet, S.; Paulus, M.; Abbott, T. M. C.; Aguena, M.; Allam, S.; Annis, J.; Benson, B. A.; Bertin, E.; Bhargava, S.; Brooks, D.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Capasso, R.; Costanzi, M.; da Costa, L. N.; De Vicente, J.; Desai, S.; Dietrich, J. P.; Doel, P.; Eifler, T. F.; Evrard, A. E.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gaztanaga, E.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Hartley, W. G.; Hinton, S. R.; Hollowood, D. L.; Honscheid, K.; James, David J.; Jeltema, T.; Kuehn, K.; Kuropatkin, N.; Lima, M.; Maia, M. A. G.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Miquel, R.; Ogando, R. L. C.; Palmese, A.; Paz-Chinchón, F.; Plazas, A. A.; Romer, A. K.; Roodman, A.; Sanchez, E.; Saro, A.; Scarpine, V.; Schubnell, M.; Serrano, S.; Sheldon, E.; Smith, M.; Stark, Antony A.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Tucker, D. L.; Varga, T. N.; Weller, J.; Wilkinson, R.
Abstract: We construct and validate the selection function of the MARD-Y3 galaxy cluster sample. This sample was selected through optical follow-up of the 2nd ROSAT faint source catalogue with Dark Energy Survey year 3 data. The selection function is modelled by combining an empirically constructed X-ray selection function with an incompleteness model for the optical follow-up. We validate the joint selection function by testing the consistency of the constraints on the X-ray flux-mass and richness-mass scaling relation parameters derived from different sources of mass information: (1) cross-calibration using South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) clusters, (2) calibration using number counts in X-ray, in optical and in both X-ray and optical while marginalizing over cosmological parameters, and (3) other published analyses. We find that the constraints on the scaling relation from the number counts and SPT-SZ cross-calibration agree, indicating that our modelling of the selection function is adequate. Furthermore, we apply a largely cosmology independent method to validate selection functions via the computation of the probability of finding each cluster in the SPT-SZ sample in the MARD-Y3 sample and vice versa. This test reveals no clear evidence for MARD-Y3 contamination, SPT-SZ incompleteness or outlier fraction. Finally, we discuss the prospects of the techniques presented here to limit systematic selection effects in future cluster cosmological studies.
The host galaxies of 106 rapidly evolving transients discovered by the Dark Energy SurveyWiseman, P.Pursiainen, M.Childress, M.Swann, E.Smith, M.Galbany, L.Lidman, C.Davis, T. M.Gutiérrez, C. P.Möller, A.Thomas, B. P.Frohmaier, C.Foley, R. J.Hinton, S. R.Kelsey, L.Kessler, R.Lewis, G. F.Sako, M.Scolnic, D.Sullivan, M.Vincenzi, M.Abbott, T. M. C.Aguena, M.Allam, S.Annis, J.Bertin, E.Bhargava, S.Brooks, D.Burke, D. L.Carnero Rosell, A.Carollo, D.Carrasco Kind, M.Carretero, J.Costanzi, M.da Costa, L. N.Diehl, H. T.Doel, P.Everett, S.Fosalba, P.Frieman, J.García-Bellido, J.Gaztanaga, E.Glazebrook, K.Gruen, D.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.Marshall, J. L.Martini, P.Menanteau, F.Miquel, R.Palmese, A.Paz-Chinchón, F.Plazas, A. A.Romer, A. K.Sanchez, E.Scarpine, V.Schubnell, M.Serrano, S.Sevilla-Noarbe, I.Sommer, N. E.Suchyta, E.Swanson, M. E. C.Tarle, G.Tucker, B. E.Tucker, D. L.Varga, T. N.Walker, A. R.DES CollaborationDOI: info:10.1093/mnras/staa2474v. 4982575–2593
Wiseman, P., Pursiainen, M., Childress, M., Swann, E., Smith, M., Galbany, L., Lidman, C., Davis, T. M., Gutiérrez, C. P., Möller, A., Thomas, B. P., Frohmaier, C., Foley, R. J., Hinton, S. R., Kelsey, L., Kessler, R., Lewis, G. F., Sako, M., Scolnic, D., Sullivan, M., Vincenzi, M., Abbott, T. M. C., Aguena, M., Allam, S., Annis, J. et al. 2020. "The host galaxies of 106 rapidly evolving transients discovered by the Dark Energy Survey." Monthly Notices of the Royal Astronomical Society 498:2575– 2593. https://doi.org/10.1093/mnras/staa2474
ID: 157812
Type: article
Authors: Wiseman, P.; Pursiainen, M.; Childress, M.; Swann, E.; Smith, M.; Galbany, L.; Lidman, C.; Davis, T. M.; Gutiérrez, C. P.; Möller, A.; Thomas, B. P.; Frohmaier, C.; Foley, R. J.; Hinton, S. R.; Kelsey, L.; Kessler, R.; Lewis, G. F.; Sako, M.; Scolnic, D.; Sullivan, M.; Vincenzi, M.; Abbott, T. M. C.; Aguena, M.; Allam, S.; Annis, J.; Bertin, E.; Bhargava, S.; Brooks, D.; Burke, D. L.; Carnero Rosell, A.; Carollo, D.; Carrasco Kind, M.; Carretero, J.; Costanzi, M.; da Costa, L. N.; Diehl, H. T.; Doel, P.; Everett, S.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gaztanaga, E.; Glazebrook, K.; Gruen, D.; 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.; Marshall, J. L.; Martini, P.; Menanteau, F.; Miquel, R.; Palmese, A.; Paz-Chinchón, F.; Plazas, A. A.; Romer, A. K.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Serrano, S.; Sevilla-Noarbe, I.; Sommer, N. E.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Tucker, B. E.; Tucker, D. L.; Varga, T. N.; Walker, A. R.; DES Collaboration
Abstract: Rapidly evolving transients (RETs), also termed fast blue optical transients, are a recently discovered group of astrophysical events that display rapid luminosity evolution. RETs typically rise to peak in less than 10 d and fade within 30, a time-scale unlikely to be compatible with the decay of Nickel-56 that drives conventional supernovae (SNe). Their peak luminosity spans a range of -15 g ∼ -9.6), indicating a link to young stellar populations, similar to stripped-envelope SNe. RET hosts appear to show a lack of chemical enrichment, their metallicities akin to long-duration gamma-ray bursts and superluminous SN host galaxies ( ∼ 9.4). There are no clear relationships between mass or SFR of the host galaxies and the peak magnitudes or decline rates of the transients themselves.
Measurements and semi-empirical calculations of CO2 + CH4 and CO2 + H2 collision-induced absorption across a wide range of wavelengths and temperatures. Application for the prediction of early Mars surface temperatureTurbet, MartinBoulet, ChristianKarman, TijsDOI: info:10.1016/j.icarus.2020.113762v. 346113762
Turbet, Martin, Boulet, Christian, and Karman, Tijs. 2020. "Measurements and semi-empirical calculations of CO2 + CH4 and CO2 + H2 collision-induced absorption across a wide range of wavelengths and temperatures. Application for the prediction of early Mars surface temperature." Icarus 346:113762. https://doi.org/10.1016/j.icarus.2020.113762
ID: 157813
Type: article
Authors: Turbet, Martin; Boulet, Christian; Karman, Tijs
Abstract: Reducing atmospheres have recently emerged as a promising scenario to warm the surface of early Mars enough to drive the formation of valley networks and other ancient aqueous features that have been detected so far on the surface of Mars. Here we present a series of experiments and calculations to better constrain CO2 + CH4 and CO2 + H2 collision-induced absorptions (CIAs) as well as their effect on the prediction of early Mars surface temperature. First, we carried out a new set of experimental measurements (using the AILES line of the SOLEIL synchrotron) of both CO2 + CH4 and CO2 + H2 CIAs. These measurements confirm the previous results of Turbet et al. (2019), Icarus vol. 321, while significantly reducing the experimental uncertainties. Secondly, we fitted a semi-empirical model to these CIAs measurements, allowing us to compute the CO2 + CH4 and CO2 + H2 CIAs across a broad spectral domain (0-1500 cm-1) and for a wide range of temperatures (100-600 K). Last, we performed 1-D numerical radiative-convective climate calculations (using the LMD Generic Model) to compute the surface temperature expected on the surface of early Mars for several CO2, CH4 and H2 atmospheric contents, taking into account the radiative effect of these revised CIAs. These calculations demonstrate that thick CO2 + H2-dominated atmospheres remain a viable solution for warming the surface of Mars above the melting point of water, but not CO2 + CH4-dominated atmospheres. Our calculated CO2 + CH4 and CO2 + H2 CIA spectra and predicted early Mars surface temperatures are provided to the community for future uses.
Discovery of the Optical Afterglow and Host Galaxy of Short GRB 181123B at z = 1.754: Implications for Delay Time DistributionsPaterson, K.Fong, W.Nugent, A.Escorial, A. RoucoLeja, JoelLaskar, T.Chornock, R.Miller, A. A.Scharwächter, J.Cenko, S. B.Perley, D.Tanvir, N. R.Levan, A.Cucchiara, A.Cobb, B. E.de, K.Berger, EdoTerreran, G.Alexander, K. D.Nicholl, M.Blanchard, P. K.Cornish, D.DOI: info:10.3847/2041-8213/aba4b0v. 898L32
Paterson, K., Fong, W., Nugent, A., Escorial, A. Rouco, Leja, Joel, Laskar, T., Chornock, R., Miller, A. A., Scharwächter, J., Cenko, S. B., Perley, D., Tanvir, N. R., Levan, A., Cucchiara, A., Cobb, B. E., de, K., Berger, Edo, Terreran, G., Alexander, K. D., Nicholl, M., Blanchard, P. K., and Cornish, D. 2020. "Discovery of the Optical Afterglow and Host Galaxy of Short GRB 181123B at z = 1.754: Implications for Delay Time Distributions." The Astrophysical Journal 898:L32. https://doi.org/10.3847/2041-8213/aba4b0
ID: 157814
Type: article
Authors: Paterson, K.; Fong, W.; Nugent, A.; Escorial, A. Rouco; Leja, Joel; Laskar, T.; Chornock, R.; Miller, A. A.; Scharwächter, J.; Cenko, S. B.; Perley, D.; Tanvir, N. R.; Levan, A.; Cucchiara, A.; Cobb, B. E.; de, K.; Berger, Edo; Terreran, G.; Alexander, K. D.; Nicholl, M.; Blanchard, P. K.; Cornish, D.
Abstract: We present the discovery of the optical afterglow and host galaxy of the Swift short-duration gamma-ray burst (SGRB) GRB 181123B. Observations with Gemini-North starting ≍9.1 hr after the burst reveal a faint optical afterglow with i ≍ 25.1 mag at an angular offset of 0"59 ± 0"16 from its host galaxy. Using grizYJHK observations, we measure a photometric redshift of the host galaxy of $z={1.77}_{-0.17}^{+0.30}$ . From a combination of Gemini and Keck spectroscopy of the host galaxy spanning 4500-18000 Å, we detect a single emission line at 13390 Å, inferred as Hβ at z = 1.754 ± 0.001 and corroborating the photometric redshift. The host galaxy properties of GRB 181123B are typical of those of other SGRB hosts, with an inferred stellar mass of ≍9.1 × 109 M, a mass-weighted age of ≍0.9 Gyr, and an optical luminosity of ≍0.9L*. At z = 1.754, GRB 181123B is the most distant secure SGRB with an optical afterglow detection and one of only three at z > 1.5. Motivated by a growing number of high-z SGRBs, we explore the effects of a missing z > 1.5 SGRB population among the current Swift sample on delay time distribution (DTD) models. We find that lognormal models with mean delay times of ≍4-6 Gyr are consistent with the observed distribution but can be ruled out to 95% confidence, with an additional ≍one to five Swift SGRBs recovered at z > 1.5. In contrast, power-law models with ∝t-1 are consistent with the redshift distribution and can accommodate up to ≍30 SGRBs at these redshifts. Under this model, we predict that ≍1/3 of the current Swift population of SGRBs is at z > 1. The future discovery or recovery of existing high-z SGRBs will provide significant discriminating power on their DTDs and thus their formation channels.
Ubiquitous NH3 supersonic component in L1688 coherent coresChoudhury, SpandanPineda, Jaime E.Caselli, PaolaGinsburg, AdamOffner, Stella S. R.Rosolowsky, ErikFriesen, Rachel K.Alves, Felipe O.Chacón-Tanarro, AnaPunanova, AnnaRedaelli, ElenaKirk, HelenMyers, Philip C.Martin, Peter G.Shirley, YancyChun-Yuan Chen, MichaelGoodman, Alyssa A.di Francesco, JamesDOI: info:10.1051/0004-6361/202037955v. 640L6
Choudhury, Spandan, Pineda, Jaime E., Caselli, Paola, Ginsburg, Adam, Offner, Stella S. R., Rosolowsky, Erik, Friesen, Rachel K., Alves, Felipe O., Chacón-Tanarro, Ana, Punanova, Anna, Redaelli, Elena, Kirk, Helen, Myers, Philip C., Martin, Peter G., Shirley, Yancy, Chun-Yuan Chen, Michael, Goodman, Alyssa A., and di Francesco, James. 2020. "Ubiquitous NH3 supersonic component in L1688 coherent cores." Astronomy and Astrophysics 640:L6. https://doi.org/10.1051/0004-6361/202037955
ID: 157815
Type: article
Authors: Choudhury, Spandan; Pineda, Jaime E.; Caselli, Paola; Ginsburg, Adam; Offner, Stella S. R.; Rosolowsky, Erik; Friesen, Rachel K.; Alves, Felipe O.; Chacón-Tanarro, Ana; Punanova, Anna; Redaelli, Elena; Kirk, Helen; Myers, Philip C.; Martin, Peter G.; Shirley, Yancy; Chun-Yuan Chen, Michael; Goodman, Alyssa A.; di Francesco, James
Abstract: Context. Star formation takes place in cold dense cores in molecular clouds. Earlier observations have found that dense cores exhibit subsonic non-thermal velocity dispersions. In contrast, CO observations show that the ambient large-scale cloud is warmer and has supersonic velocity dispersions. Aims: We aim to study the ammonia (NH3) molecular line profiles with exquisite sensitivity towards the coherent cores in L1688 in order to study their kinematical properties in unprecedented detail. Methods: We used NH3 (1,1) and (2,2) data from the first data release (DR1) in the Green Bank Ammonia Survey (GAS). We first smoothed the data to a larger beam of 1' to obtain substantially more extended maps of velocity dispersion and kinetic temperature, compared to the DR1 maps. We then identified the coherent cores in the cloud and analysed the averaged line profiles towards the cores. Results: For the first time, we detected a faint (mean NH3(1,1) peak brightness (1,1) peak brightness MB), supersonic component towards all the coherent cores in L1688. We fitted two components, one broad and one narrow, and derived the kinetic temperature and velocity dispersion of each component. The broad components towards all cores have supersonic linewidths (ℳS ≥ 1). This component biases the estimate of the narrow dense core component's velocity dispersion by ≈28% and the kinetic temperature by ≈10%, on average, as compared to the results from single-component fits. Conclusions: Neglecting this ubiquitous presence of a broad component towards all coherent cores causes the typical single-component fit to overestimate the temperature and velocity dispersion. This affects the derived detailed physical structure and stability of the cores estimated from NH3 observations.
DEATHSTAR: Nearby AGB stars with the Atacama Compact Array. I. CO envelope sizes and asymmetries: A new hope for accurate mass-loss-rate estimatesRamstedt, S.Vlemmings, W. H. T.Doan, L.Danilovich, T.Lindqvist, M.Saberi, M.Olofsson, H.De Beck, E.Groenewegen, M. A. T.Höfner, S.Kastner, J. H.Kerschbaum, F.Khouri, T.Maercker, M.Montez, RodolfoQuintana-Lacaci, G.Sahai, R.Tafoya, D.Zijlstra, A.DOI: info:10.1051/0004-6361/201936874v. 640A133
Ramstedt, S., Vlemmings, W. H. T., Doan, L., Danilovich, T., Lindqvist, M., Saberi, M., Olofsson, H., De Beck, E., Groenewegen, M. A. T., Höfner, S., Kastner, J. H., Kerschbaum, F., Khouri, T., Maercker, M., Montez, Rodolfo, Quintana-Lacaci, G., Sahai, R., Tafoya, D., and Zijlstra, A. 2020. "DEATHSTAR: Nearby AGB stars with the Atacama Compact Array. I. CO envelope sizes and asymmetries: A new hope for accurate mass-loss-rate estimates." Astronomy and Astrophysics 640:A133. https://doi.org/10.1051/0004-6361/201936874
ID: 157816
Type: article
Authors: Ramstedt, S.; Vlemmings, W. H. T.; Doan, L.; Danilovich, T.; Lindqvist, M.; Saberi, M.; Olofsson, H.; De Beck, E.; Groenewegen, M. A. T.; Höfner, S.; Kastner, J. H.; Kerschbaum, F.; Khouri, T.; Maercker, M.; Montez, Rodolfo; Quintana-Lacaci, G.; Sahai, R.; Tafoya, D.; Zijlstra, A.
Abstract: Context. This is the first publication from the DEATHSTAR project. The overall goal of the project is to reduce the uncertainties of the observational estimates of mass-loss rates from evolved stars on the Asymptotic Giant Branch (AGB). Aim. The aim in this first publication is to constrain the sizes of the 12CO emitting region from the circumstellar envelopes around 42 mostly southern AGB stars, of which 21 are M-type and 21 are C-type, using the Atacama Compact Array (ACA) at the Atacama Large Millimeter/submillimeter Array. The symmetry of the outflows is also investigated. Methods: Line emission from 12CO J = 2→1 and 3→2 from all of the sources were mapped using the ACA. In this initial analysis, the emission distribution was fit to a Gaussian distribution in the uv-plane. A detailed radiative transfer analysis will be presented in a future publication. The major and minor axis of the best-fit Gaussian at the line center velocity of the 12CO J = 2→1 emission gives a first indication of the size of the emitting region. Furthermore, the fitting results, such as the Gaussian major and minor axis, center position, and the goodness of fit across both lines, constrain the symmetry of the emission distribution. For a subsample of sources, the measured emission distribution is compared to predictions from previous best-fit radiative transfer modeling results. Results: We find that the CO envelope sizes are, in general, larger for C-type than for M-type AGB stars, which is as expected if the CO/H2 ratio is larger in C-type stars. Furthermore, the measurements show a relation between the measured (Gaussian) 12CO J = 2→1 size and circumstellar density that, while in broad agreement with photodissociation calculations, reveals large scatter and some systematic differences between the different stellar types. For lower mass-loss-rate irregular and semi-regular variables of both M- and C-type AGB stars, the 12CO J = 2→1 size appears to be independent of the ratio of the mass-loss rate to outflow velocity, which is a measure of circumstellar density. For the higher mass-loss-rate Mira stars, the 12CO J = 2→1 size clearly increases with circumstellar density, with larger sizes for the higher CO-abundance C-type stars. The M-type stars appear to be consistently smaller than predicted from photodissociation theory. The majority of the sources have CO envelope sizes that are consistent with a spherically symmetric, smooth outflow, at least on larger scales. For about a third of the sources, indications of strong asymmetries are detected. This is consistent with what was found in previous interferometric investigations of northern sources. Smaller scale asymmetries are found in a larger fraction of sources. Conclusions: These results for CO envelope radii and shapes can be used to constrain detailed radiative transfer modeling of the same stars so as to determine mass-loss rates that are independent of photodissociation models. For a large fraction of the sources, observations at higher spatial resolution will be necessary to deduce the nature and origin of the complex circumstellar dynamics revealed by our ACA observations.The reduced datacubes 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/640/A133
The Proper Motion of the Central Compact Object RX J0822-4300 in the Supernova Remnant Puppis A, RevisitedMayer, MartinBecker, WernerPatnaude, DanielWinkler, P. FrankKraft, RalphDOI: info:10.3847/1538-4357/aba121v. 899138
Mayer, Martin, Becker, Werner, Patnaude, Daniel, Winkler, P. Frank, and Kraft, Ralph. 2020. "The Proper Motion of the Central Compact Object RX J0822-4300 in the Supernova Remnant Puppis A, Revisited." The Astrophysical Journal 899:138. https://doi.org/10.3847/1538-4357/aba121
ID: 157817
Type: article
Authors: Mayer, Martin; Becker, Werner; Patnaude, Daniel; Winkler, P. Frank; Kraft, Ralph
Abstract: We present an improved proper-motion measurement of the central compact object RX J0822-4300, located in the supernova remnant Puppis A. By employing a new data set taken in 2019 February by the High Resolution Camera on board the Chandra X-ray Observatory, we approximately double the available temporal baseline for our analysis to slightly more than 19 yr (7000 days). We correct for the astrometric inaccuracy of Chandra using calibrator stars with known optical positions that are detected in all observations. Thereby, we obtain absolute positions of RX J0822-4300 accurate to around $0\buildrel{\prime\prime}\over{.} 1$ and from these a new best estimate for its total proper motion of ${\mu }_{\mathrm{tot}}=(80.4\pm 7.7)\,\mathrm{mas}\,{\mathrm{yr}}^{-1}$. For a remnant distance of 2 kpc, this corresponds to a projected kick velocity of $(763\pm 73)\ \,\mathrm{km}\,{{\rm{s}}}^{-1}$ at a position angle of ${\phi }_{0}={(247.8\pm 4.4)}^{\circ }$. The proper-motion measurement of RX J0822-4300 is used for discussing the kinematic age of Puppis A.
SN 2019ehk: A Double-peaked Ca-rich Transient with Luminous X-Ray Emission and Shock-ionized Spectral FeaturesJacobson-Galán, Wynn V.Margutti, RaffaellaKilpatrick, Charles D.Hiramatsu, DaichiPerets, HagaiKhatami, DavidFoley, Ryan J.Raymond, JohnYoon, Sung-ChulBobrick, AlexeyZenati, YossefGalbany, LluísAndrews, JenniferBrown, Peter J.Cartier, RégisCoppejans, Deanne L.Dimitriadis, GeorgiosDobson, MatthewHajela, AprajitaHowell, D. AndrewKuncarayakti, HanindyoMilisavljevic, DannyRahman, MohammedRojas-Bravo, CésarSand, David J.Shepherd, JoelSmartt, Stephen J.Stacey, HollandStroh, MichaelSwift, Jonathan J.Terreran, GiacomoVinko, JozsefWang, XiaofengAnderson, Joseph P.Baron, Edward A.Berger, EdoBlanchard, Peter K.Burke, JamisonCoulter, David A.DeMarchi, LindsayDerkacy, James M.Fremling, ChristofferGomez, SebastianGromadzki, MariuszHosseinzadeh, GriffinKasen, DanielKriskovics, LeventeMcCully, CurtisMüller-Bravo, Tomás E.Nicholl, MattOrdasi, AndrásPellegrino, CraigPiro, Anthony L.Pál, AndrásRen, JuanjuanRest, ArminRich, R. MichaelSai, HannaSárneczky, KrisztiánShen, Ken J.Short, PhilipSiebert, Matthew R.Stauffer, CandiceSzakáts, RóbertZhang, XinhanZhang, JujiaZhang, KaichengDOI: info:10.3847/1538-4357/ab9e66v. 898166
Jacobson-Galán, Wynn V., Margutti, Raffaella, Kilpatrick, Charles D., Hiramatsu, Daichi, Perets, Hagai, Khatami, David, Foley, Ryan J., Raymond, John, Yoon, Sung-Chul, Bobrick, Alexey, Zenati, Yossef, Galbany, Lluís, Andrews, Jennifer, Brown, Peter J., Cartier, Régis, Coppejans, Deanne L., Dimitriadis, Georgios, Dobson, Matthew, Hajela, Aprajita, Howell, D. Andrew, Kuncarayakti, Hanindyo, Milisavljevic, Danny, Rahman, Mohammed, Rojas-Bravo, César, Sand, David J. et al. 2020. "SN 2019ehk: A Double-peaked Ca-rich Transient with Luminous X-Ray Emission and Shock-ionized Spectral Features." The Astrophysical Journal 898:166. https://doi.org/10.3847/1538-4357/ab9e66
ID: 157818
Type: article
Authors: Jacobson-Galán, Wynn V.; Margutti, Raffaella; Kilpatrick, Charles D.; Hiramatsu, Daichi; Perets, Hagai; Khatami, David; Foley, Ryan J.; Raymond, John; Yoon, Sung-Chul; Bobrick, Alexey; Zenati, Yossef; Galbany, Lluís; Andrews, Jennifer; Brown, Peter J.; Cartier, Régis; Coppejans, Deanne L.; Dimitriadis, Georgios; Dobson, Matthew; Hajela, Aprajita; Howell, D. Andrew; Kuncarayakti, Hanindyo; Milisavljevic, Danny; Rahman, Mohammed; Rojas-Bravo, César; Sand, David J.; Shepherd, Joel; Smartt, Stephen J.; Stacey, Holland; Stroh, Michael; Swift, Jonathan J.; Terreran, Giacomo; Vinko, Jozsef; Wang, Xiaofeng; Anderson, Joseph P.; Baron, Edward A.; Berger, Edo; Blanchard, Peter K.; Burke, Jamison; Coulter, David A.; DeMarchi, Lindsay; Derkacy, James M.; Fremling, Christoffer; Gomez, Sebastian; Gromadzki, Mariusz; Hosseinzadeh, Griffin; Kasen, Daniel; Kriskovics, Levente; McCully, Curtis; Müller-Bravo, Tomás E.; Nicholl, Matt; Ordasi, András; Pellegrino, Craig; Piro, Anthony L.; Pál, András; Ren, Juanjuan; Rest, Armin; Rich, R. Michael; Sai, Hanna; Sárneczky, Krisztián; Shen, Ken J.; Short, Philip; Siebert, Matthew R.; Stauffer, Candice; Szakáts, Róbert; Zhang, Xinhan; Zhang, Jujia; Zhang, Kaicheng
Abstract: We present panchromatic observations and modeling of the Calcium-rich supernova (SN) 2019ehk in the star-forming galaxy M100 (d ≍ 16.2 Mpc) starting 10 hr after explosion and continuing for ∼300 days. SN 2019ehk shows a double-peaked optical light curve peaking at t = 3 and 15 days. The first peak is coincident with luminous, rapidly decaying Swift-XRT-discovered X-ray emission ( ${L}_{{\rm{x}}}\approx {10}^{41}\,\mathrm{erg}\,{{\rm{s}}}^{-1}$ at 3 days; Lx ∝ t-3), and a Shane/Kast spectral detection of narrow Hα and He II emission lines (v ≍ 500 $\mathrm{km}\,{{\rm{s}}}^{-1}$ ) originating from pre-existent circumstellar material (CSM). We attribute this phenomenology to radiation from shock interaction with extended, dense material surrounding the progenitor star at r ), and a Shane/Kast spectral detection of narrow Hα and He II emission lines (v ≍ 500 $\mathrm{km}\,{{\rm{s}}}^{-1}$ ) originating from pre-existent circumstellar material (CSM). We attribute this phenomenology to radiation from shock interaction with extended, dense material surrounding the progenitor star at r 15 cm and the resulting cooling emission. We calculate a total CSM mass of ∼7 × 10-3 ${M}_{\odot }$ (MHe/MH ≍6) with particle density n ≍ 109 cm-3. Radio observations indicate a significantly lower density n . Radio observations indicate a significantly lower density n 4 cm-3 at larger radii r > (0.1-1) × 1017 cm. The photometric and spectroscopic properties during the second light-curve peak are consistent with those of Ca-rich transients (rise-time of tr = 13.4 ± 0.210 days and a peak B-band magnitude of MB = -15.1 ± 0.200 mag). We find that SN 2019ehk synthesized (3.1 ± 0.11) × 10-2 ${M}_{\odot }$ of ${}^{56}\mathrm{Ni}$ and ejected Mej = (0.72 ± 0.040) ${M}_{\odot }$ total with a kinetic energy Ek = (1.8 ± 0.10) × 1050 erg. Finally, deep HST pre-explosion imaging at the SN site constrains the parameter space of viable stellar progenitors to massive stars in the lowest mass bin (∼10 ${M}_{\odot }$ ) in binaries that lost most of their He envelope or white dwarfs (WDs). The explosion and environment properties of SN 2019ehk further restrict the potential WD progenitor systems to low-mass hybrid HeCO WD+CO WD binaries.
Simultaneous observations of the blazar PKS 2155-304 from ultra-violet to TeV energiesAbdalla, H.Adam, R.Aharonian, F.Ait Benkhali, F.Angüner, E. O.Arakawa, M.Arcaro, C.Armand, C.Ashkar, H.Backes, M.Barbosa Martins, V.Barnard, M.Becherini, Y.Berge, D.Bernlöhr, K.Blackwell, R.Böttcher, M.Boisson, C.Bolmont, J.Bonnefoy, S.Bregeon, J.Breuhaus, M.Brun, F.Brun, P.Bryan, M.Büchele, M.Bulik, T.Bylund, T.Caroff, S.Carosi, A.Casanova, S.Cerruti, M.Chand, T.Chandra, S.Chen, A.Colafrancesco, S.Curyło, M.Davids, I. D.Deil, C.Devin, J.deWilt, P.Dirson, L.Djannati-Ataï, A.Dmytriiev, A.Donath, A.Doroshenko, V.Dyks, J.Egberts, K.Emery, G.Ernenwein, J. -PEschbach, S.Feijen, K.Fegan, S.Fiasson, A.Fontaine, G.Funk, S.Füßling, M.Gabici, S.Gallant, Y. A.Gaté, F.Giavitto, G.Giunti, L.Glawion, D.Glicenstein, J. F.Gottschall, D.Grondin, M. -HHahn, J.Haupt, M.Heinzelmann, G.Henri, G.Hermann, G.Hinton, J. A.Hofmann, W.Hoischen, C.Holch, T. L.Holler, M.Horns, D.Huber, D.Iwasaki, H.Jamrozy, M.Jankowsky, D.Jankowsky, F.Jardin-Blicq, A.Jung-Richardt, I.Kastendieck, M. A.Katarzyński, K.Katsuragawa, M.Katz, U.Khangulyan, D.Khélifi, B.King, J.Klepser, S.Kluźniak, W.Komin, NuKosack, K.Kostunin, D.Kreter, M.Lamanna, G.Lemière, A.Lemoine-Goumard, M.Lenain, J. -PLeser, E.Levy, C.Lohse, T.Lypova, I.Mackey, J.Majumdar, J.Malyshev, D.Marandon, V.Marcowith, A.Mares, A.Mariaud, C.Martí-Devesa, G.Marx, R.Maurin, G.Meintjes, P. J.Mitchell, A. M. W.Moderski, R.Mohamed, M.Mohrmann, L.Moore, C.Moulin, E.Muller, J.Murach, T.Nakashima, S.de Naurois, M.Ndiyavala, H.Niederwanger, F.Niemiec, J.Oakes, L.O'Brien, P.Odaka, H.Ohm, S.de Ona Wilhelmi, E.Ostrowski, M.Oya, I.Panter, M.Parsons, R. D.Perennes, C.Petrucci, P. -OPeyaud, B.Piel, Q.Pita, S.Poireau, V.Priyana Noel, A.Prokhorov, D. A.Prokoph, H.Pühlhofer, G.Punch, M.Quirrenbach, A.Raab, S.Rauth, R.Reimer, A.Reimer, O.Remy, Q.Renaud, M.Rieger, F.Rinchiuso, L.Romoli, C.Rowell, G.Rudak, B.Ruiz-Velasco, E.Sahakian, V.Sailer, S.Saito, S.Sanchez, D. A.Santangelo, A.Sasaki, M.Schlickeiser, R.Schüssler, F.Schulz, A.Schutte, H. M.Schwanke, U.Schwemmer, S.Seglar-Arroyo, M.Senniappan, M.Seyffert, A. S.Shafi, N.Shiningayamwe, K.Simoni, R.Sinha, A.Sol, H.Specovius, A.Spir-Jacob, M.Stawarz, Ł.Steenkamp, R.Stegmann, C.Steppa, C.Takahashi, T.Tavernier, T.Taylor, A. M.Terrier, R.Tiziani, D.Tluczykont, M.Trichard, C.Tsirou, M.Tsuji, N.Tuffs, R.Uchiyama, Y.van der Walt, D. J.van Eldik, C.van Rensburg, C.van Soelen, B.Vasileiadis, G.Veh, J.Venter, C.Vincent, P.Vink, J.Völk, H. J.Vuillaume, T.Wadiasingh, Z.Wagner, S. J.White, R.Wierzcholska, A.Yang, R.Yoneda, H.Zacharias, M.Zanin, R.Zdziarski, A. A.Zech, A.Zorn, J.Żywucka, N.Madejski, G. M.Nalewajko, K.Madsen, K. K.Chiang, J.Baloković, MislavPaneque, D.Furniss, A. K.Hayashida, M.Urry, C. M.Ajello, M.Harrison, F. A.Giebels, B.Stern, D.Forster, K.Giommi, P.Perri, M.Puccetti, S.Zoglauer, A.Tagliaferri, G.DOI: info:10.1051/0004-6361/201936900v. 639A42
Abdalla, H., Adam, R., Aharonian, F., Ait Benkhali, F., Angüner, E. O., Arakawa, M., Arcaro, C., Armand, C., Ashkar, H., Backes, M., Barbosa Martins, V., Barnard, M., Becherini, Y., Berge, D., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bregeon, J., Breuhaus, M., Brun, F., Brun, P., Bryan, M. et al. 2020. "Simultaneous observations of the blazar PKS 2155-304 from ultra-violet to TeV energies." Astronomy and Astrophysics 639:A42. https://doi.org/10.1051/0004-6361/201936900
ID: 157819
Type: article
Authors: Abdalla, H.; Adam, R.; Aharonian, F.; Ait Benkhali, F.; Angüner, E. O.; Arakawa, M.; Arcaro, C.; Armand, C.; Ashkar, H.; Backes, M.; Barbosa Martins, V.; Barnard, M.; Becherini, Y.; Berge, D.; Bernlöhr, K.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bonnefoy, S.; Bregeon, J.; Breuhaus, M.; Brun, F.; Brun, P.; Bryan, M.; Büchele, M.; Bulik, T.; Bylund, T.; Caroff, S.; Carosi, A.; Casanova, S.; Cerruti, M.; Chand, T.; Chandra, S.; Chen, A.; Colafrancesco, S.; Curyło, M.; Davids, I. D.; Deil, C.; Devin, J.; deWilt, P.; Dirson, L.; Djannati-Ataï, A.; Dmytriiev, A.; Donath, A.; Doroshenko, V.; Dyks, J.; Egberts, K.; Emery, G.; Ernenwein, J. -P; Eschbach, S.; Feijen, K.; Fegan, S.; Fiasson, A.; Fontaine, G.; Funk, S.; Füßling, M.; Gabici, S.; Gallant, Y. A.; Gaté, F.; Giavitto, G.; Giunti, L.; Glawion, D.; Glicenstein, J. F.; Gottschall, D.; Grondin, M. -H; Hahn, J.; Haupt, M.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holch, T. L.; Holler, M.; Horns, D.; Huber, D.; Iwasaki, H.; Jamrozy, M.; Jankowsky, D.; Jankowsky, F.; Jardin-Blicq, A.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katsuragawa, M.; Katz, U.; Khangulyan, D.; Khélifi, B.; King, J.; Klepser, S.; Kluźniak, W.; Komin, Nu; Kosack, K.; Kostunin, D.; Kreter, M.; Lamanna, G.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J. -P; Leser, E.; Levy, C.; Lohse, T.; Lypova, I.; Mackey, J.; Majumdar, J.; Malyshev, D.; Marandon, V.; Marcowith, A.; Mares, A.; Mariaud, C.; Martí-Devesa, G.; Marx, R.; Maurin, G.; Meintjes, P. J.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mohrmann, L.; Moore, C.; Moulin, E.; Muller, J.; Murach, T.; Nakashima, S.; de Naurois, M.; Ndiyavala, H.; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Ohm, S.; de Ona Wilhelmi, E.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Perennes, C.; Petrucci, P. -O; Peyaud, B.; Piel, Q.; Pita, S.; Poireau, V.; Priyana Noel, A.; Prokhorov, D. A.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Rauth, R.; Reimer, A.; Reimer, O.; Remy, Q.; Renaud, M.; Rieger, F.; Rinchiuso, L.; Romoli, C.; Rowell, G.; Rudak, B.; Ruiz-Velasco, E.; Sahakian, V.; Sailer, S.; Saito, S.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schutte, H. M.; Schwanke, U.; Schwemmer, S.; Seglar-Arroyo, M.; Senniappan, M.; Seyffert, A. S.; Shafi, N.; Shiningayamwe, K.; Simoni, R.; Sinha, A.; Sol, H.; Specovius, A.; Spir-Jacob, M.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Steppa, C.; Takahashi, T.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tiziani, D.; Tluczykont, M.; Trichard, C.; Tsirou, M.; Tsuji, N.; Tuffs, R.; Uchiyama, Y.; van der Walt, D. J.; van Eldik, C.; van Rensburg, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Vincent, P.; Vink, J.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; White, R.; Wierzcholska, A.; Yang, R.; Yoneda, H.; Zacharias, M.; Zanin, R.; Zdziarski, A. A.; Zech, A.; Zorn, J.; Żywucka, N.; Madejski, G. M.; Nalewajko, K.; Madsen, K. K.; Chiang, J.; Baloković, Mislav; Paneque, D.; Furniss, A. K.; Hayashida, M.; Urry, C. M.; Ajello, M.; Harrison, F. A.; Giebels, B.; Stern, D.; Forster, K.; Giommi, P.; Perri, M.; Puccetti, S.; Zoglauer, A.; Tagliaferri, G.
Abstract: Here we report the results of the first ever contemporaneous multi-wavelength observation campaign on the BL Lac object PKS 2155-304 involving Swift, NuSTAR, Fermi-LAT, and H.E.S.S. The use of these instruments allows us to cover a broad energy range, which is important for disentangling the different radiative mechanisms. The source, observed from June 2013 to October 2013, was found in a low flux state with respect to previous observations but exhibited highly significant flux variability in the X-rays. The high-energy end of the synchrotron spectrum can be traced up to 40 keV without significant contamination by high-energy emission. A one-zone synchrotron self-Compton model was used to reproduce the broadband flux of the source for all the observations presented here but failed for previous observations made in April 2013. A lepto-hadronic solution was then explored to explain these earlier observational results.
Toward the low-scatter selection of X-ray clusters. Galaxy cluster detection with eROSITA through cluster outskirtsKäfer, FlorianFinoguenov, AlexisEckert, DominiqueClerc, NicolasRamos-Ceja, Miriam E.Sanders, Jeremy S.Ghirardini, VittorioDOI: info:10.1051/0004-6361/201936131v. 634A8
Käfer, Florian, Finoguenov, Alexis, Eckert, Dominique, Clerc, Nicolas, Ramos-Ceja, Miriam E., Sanders, Jeremy S., and Ghirardini, Vittorio. 2020. "Toward the low-scatter selection of X-ray clusters. Galaxy cluster detection with eROSITA through cluster outskirts." Astronomy and Astrophysics 634:A8. https://doi.org/10.1051/0004-6361/201936131
ID: 157748
Type: article
Authors: Käfer, Florian; Finoguenov, Alexis; Eckert, Dominique; Clerc, Nicolas; Ramos-Ceja, Miriam E.; Sanders, Jeremy S.; Ghirardini, Vittorio
Abstract: Context. One key ingredient in using galaxy clusters as a precision cosmological probe in large X-ray surveys is understanding selection effects. The dependence of the X-ray emission on the square of the gas density leads to a predominant role of cool cores in the detection of galaxy clusters. The contribution of cool cores to the X-ray luminosity does not scale with cluster mass and cosmology and therefore affects the use of X-ray clusters in producing cosmological constraints.
Aims: One of the main science goals of the extended ROentgen Survey with an Imaging Telescope Array (eROSITA) mission is to constrain cosmology with a wide X-ray survey. We propose an eROSITA galaxy cluster detection scheme that avoids the use of X-ray cluster centers in detection. We calculate theoretical expectations and characterize the performance of this scheme by simulations.
Methods: We performed Monte Carlo simulations of the upcoming eROSITA mission, including known foreground and background components. By performing realistic simulations of point sources in survey mode, we searched for spatial scales where the extended signal is not contaminated by the point-source flux. We derive a combination of scales and thresholds, which result in a clean extended source catalog. We designed the output of the cluster detection, which enables calibrating the core-excised luminosity using external mass measurements. We provide a way to incorporate the results of this calibration in producing the final core-excised luminosity.
Results: Similarly to other galaxy cluster detection pipelines, we sample the detection space of the flux - cluster core radius of our method and find many similarities with the pipeline used in the 400d survey. Both detection methods require large statistics on compact clusters in order to reduce the contamination from point sources. The benefit of our pipeline consists of the sensitivity to the outer cluster shapes, which are characterized by large core sizes with little cluster to cluster variation at a fixed total mass of the cluster.
Conclusions: Galaxy cluster detection through cluster outskirts improves the cluster characterization using eROSITA survey data and is expected to yield well-characterized cluster catalogs with simple selection functions.
Protostellar disk formation by a nonrotating, nonaxisymmetric collapsing cloud: model and comparison with observationsVerliat, AntoineHennebelle, PatrickMaury, Anaëlle J.Gaudel, MathildeDOI: info:10.1051/0004-6361/201936394v. 635A130
Verliat, Antoine, Hennebelle, Patrick, Maury, Anaëlle J., and Gaudel, Mathilde. 2020. "Protostellar disk formation by a nonrotating, nonaxisymmetric collapsing cloud: model and comparison with observations." Astronomy and Astrophysics 635:A130. https://doi.org/10.1051/0004-6361/201936394
ID: 157749
Type: article
Authors: Verliat, Antoine; Hennebelle, Patrick; Maury, Anaëlle J.; Gaudel, Mathilde
Abstract: Context. Planet-forming disks are fundamental objects that are thought to be inherited from large scale rotation through the conservation of angular momentum during the collapse of a prestellar dense core.
Aims: We investigate the possibility for a protostellar disk to be formed from a motionless dense core that contains nonaxisymmetric density fluctuations. The rotation is thus generated locally by the asymmetry of the collapse.
Methods: We study the evolution of the angular momentum in a nonaxisymmetric collapse of a dense core from an analytical point of view. To test the theory, we performed three-dimensional simulations of a collapsing prestellar dense core using adaptative mesh refinement. We started from a nonaxisymmetrical situation, considering a dense core with random density perturbations that follow a turbulence spectrum. We analyzed the emerging disk by comparing the angular momentum it contains with the one expected from our analytic development. We studied the velocity gradients at different scales in the simulation as is done with observations.
Results: We show that the angular momentum in the frame of a stellar object, which is not located at the center of mass of the core, is not conserved due to inertial forces. Our simulations of such nonaxisymmetrical collapse quickly produce accretion disks at the small scales in the core. The analysis of the kinematics at different scales in the simulated core reveals projected velocity gradients of amplitudes similar to the ones observed in protostellar cores and for which directions vary, sometimes even reversing when small and large scales are compared. These complex kinematics patterns appear in recent observations and could be a discriminating feature with models where rotation is inherited from large scales. Our results from simulations without initial rotation are more consistent with these recent observations than when solid-body rotation is initially imprinted. Lastly, we show that the disks that formed in this scenario of nonaxisymmetrical gravitational collapse grow to reach sizes larger than those that are observed, and then fragment. We show that including a magnetic field in these simulations reduces the size of the outcoming disks and it prevents them from fragmenting, as is shown by previous studies.
Conclusions: We show that in a nonaxisymmetrical collapse, the formation of a disk can be induced by small perturbations of the initial density field in the core, even in the absence of global large-scale rotation of the core. In this scenario, large disks are generic features that are natural consequences of the hydrodynamical fluid interactions and self-gravity. Since recent observations have shown that most disks are significantly smaller and have a size of a few tens of astronomical units, our study suggests that magnetic braking is the most likely explanation. The kinematics of our model are consistent with typically observed values of velocity gradients and specific angular momentum in protostellar cores. These results open a new avenue in which our understanding of the early phases of disk formation can be explored since they suggest that a fraction of the protostellar disks could be the product of nonaxisymmetrical collapse, rather than directly resulting from the conservation of preexisting large scale angular momentum in rotating cores.
Questioning the spatial origin of complex organic molecules in young protostars with the CALYPSO surveyBelloche, A.Maury, Anaëlle J.Maret, S.Anderl, S.Bacmann, A.André, PhBontemps, S.Cabrit, S.Codella, C.Gaudel, M.Gueth, F.Lefèvre, C.Lefloch, B.Podio, L.Testi, L.DOI: info:10.1051/0004-6361/201937352v. 635A198
Belloche, A., Maury, Anaëlle J., Maret, S., Anderl, S., Bacmann, A., André, Ph, Bontemps, S., Cabrit, S., Codella, C., Gaudel, M., Gueth, F., Lefèvre, C., Lefloch, B., Podio, L., and Testi, L. 2020. "Questioning the spatial origin of complex organic molecules in young protostars with the CALYPSO survey." Astronomy and Astrophysics 635:A198. https://doi.org/10.1051/0004-6361/201937352
ID: 157750
Type: article
Authors: Belloche, A.; Maury, Anaëlle J.; Maret, S.; Anderl, S.; Bacmann, A.; André, Ph; Bontemps, S.; Cabrit, S.; Codella, C.; Gaudel, M.; Gueth, F.; Lefèvre, C.; Lefloch, B.; Podio, L.; Testi, L.
Abstract: Context. Complex organic molecules (COMs) have been detected in a few Class 0 protostars but their origin is not well understood. While the usual picture of a hot corino explains their presence as resulting from the heating of the inner envelope by the nascent protostar, shocks in the outflow, disk wind, the presence of a flared disk, or the interaction region between envelope and disk at the centrifugal barrier have also been claimed to enhance the abundance of COMs.
Aims: Going beyond studies of individual objects, we want to investigate the origin of COMs in young protostars on a statistical basis.
Methods: We use the CALYPSO survey performed with the Plateau de Bure Interferometer of the Institut de Radioastronomie Millimétrique to search for COMs at high angular resolution in a sample of 26 solar-type protostars, including 22 Class 0 and four Class I objects. We derive the column densities of the detected molecules under the local thermodynamic equilibrium approximation and search for correlations between their abundances and with various source properties.
Results: Methanol is detected in 12 sources and tentatively in one source, which represents half of the sample. Eight sources (30%) have detections of at least three COMs. We find a strong chemical differentiation in multiple systems with five systems having one component with at least three COMs detected but the other component devoid of COM emission. All sources with a luminosity higher than 4 L have at least one detected COM whereas no COM emission is detected in sources with internal luminosity lower than 2 L, likely because of a lack of sensitivity. Internal luminosity is found to be the source parameter impacting the COM chemical composition of the sources the most, while there is no obvious correlation between the detection of COM emission and that of a disk-like structure. A canonical hot-corino origin may explain the COM emission in four sources, an accretion-shock origin in two or possibly three sources, and an outflow origin in three sources. The CALYPSO sources with COM detections can be classified into three groups on the basis of the abundances of oxygen-bearing molecules, cyanides, and CHO-bearing molecules. These chemical groups correlate neither with the COM origin scenarios, nor with the evolutionary status of the sources if we take the ratio of envelope mass to internal luminosity as an evolutionary tracer. We find strong correlations between molecules that are a priori not related chemically (for instance methanol and methyl cyanide), implying that the existence of a correlation does not imply a chemical link.
Conclusions: The CALYPSO survey has revealed a chemical differentiation in multiple systems that is markedly different from the case of the prototypical binary IRAS 16293-2422. This raises the question of whether all low-mass protostars go through a phase showing COM emission. A larger sample of young protostars and a more accurate determination of their internal luminosity will be necessary to make further progress. Searching for correlations between the COM emission and the jet/outflow properties of the sources may also be promising.
Based on observations carried out with the IRAM Plateau de Bure Interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).
The CALYPSO calibrated visibility tables and maps are publicly available at http://www.iram-institute.org/EN/content-page-317-7-158-240-317-0.html
Angular momentum profiles of Class 0 protostellar envelopesGaudel, M.Maury, Anaëlle J.Belloche, A.Maret, S.André, PhHennebelle, P.Galametz, M.Testi, L.Cabrit, S.Palmeirim, P.Ladjelate, B.Codella, C.Podio, L.DOI: info:10.1051/0004-6361/201936364v. 637A92
Gaudel, M., Maury, Anaëlle J., Belloche, A., Maret, S., André, Ph, Hennebelle, P., Galametz, M., Testi, L., Cabrit, S., Palmeirim, P., Ladjelate, B., Codella, C., and Podio, L. 2020. "Angular momentum profiles of Class 0 protostellar envelopes." Astronomy and Astrophysics 637:A92. https://doi.org/10.1051/0004-6361/201936364
ID: 157751
Type: article
Authors: Gaudel, M.; Maury, Anaëlle J.; Belloche, A.; Maret, S.; André, Ph; Hennebelle, P.; Galametz, M.; Testi, L.; Cabrit, S.; Palmeirim, P.; Ladjelate, B.; Codella, C.; Podio, L.
Abstract: Context. Understanding the initial properties of star forming material and how they affect the star formation process is a key question. The infalling gas must redistribute most of its initial angular momentum inherited from prestellar cores before reaching the central stellar embryo. Disk formation has been naturally considered as a possible solution to this "angular momentum problem". However, how the initial angular momentum of protostellar cores is distributed and evolves during the main accretion phase and the beginning of disk formation has largely remained unconstrained up to now.
Aims: In the framework of the IRAM CALYPSO survey, we obtained observations of the dense gas kinematics that we used to quantify the amount and distribution of specific angular momentum at all scales in collapsing-rotating Class 0 protostellar envelopes.
Methods: We used the high dynamic range C18O (2-1) and N2H+ (1-0) datasets to produce centroid velocity maps and probe the rotational motions in the sample of 12 envelopes from scales ~50 to ~5000 au.
Results: We identify differential rotation motions at scales ≲1600 au in 11 out of the 12 protostellar envelopes of our sample by measuring the velocity gradient along the equatorial axis, which we fit with a power-law model v ∝ rα. This suggests that coherent motions dominate the kinematics in the inner protostellar envelopes. The radial distributions of specific angular momentum in the CALYPSO sample suggest the following two distinct regimes within protostellar envelopes: the specific angular momentum decreases as j ∝ r1.6±0.2 down to ~1600 au and then tends to become relatively constant around ~6 × 10-4 km s-1 pc down to ~50 au.
Conclusions: The values of specific angular momentum measured in the inner Class 0 envelopes suggest that material directly involved in the star formation process (1600 au, suggesting that these gradients may not be directly related to rotational motions of the envelopes. We conclude that the specific angular momentum observed at these scales could find its origin in other mechanisms, such as core-forming motions (infall, turbulence), or trace an imprint of the initial conditions for the formation of protostellar cores.
The datasets used in this paper are available at http://www.iram.fr/ILPA/LP010/
VVV-WIT-01: highly obscured classical nova or protostellar collision?Lucas, P. W.Minniti, D.Kamble, AtishKaplan, D. L.Cross, N.Dekany, I.Ivanov, V. D.Kurtev, R.Saito, R. K.Smith, L. C.Catelan, M.Masetti, N.Toledo, I.Hempel, M.Thompson, M. A.Contreras Peña, C.Forbrich, J.Krause, M.Dale, J.Borissova, J.Emerson, J.DOI: info:10.1093/mnras/staa155v. 4924847–4857
Lucas, P. W., Minniti, D., Kamble, Atish, Kaplan, D. L., Cross, N., Dekany, I., Ivanov, V. D., Kurtev, R., Saito, R. K., Smith, L. C., Catelan, M., Masetti, N., Toledo, I., Hempel, M., Thompson, M. A., Contreras Peña, C., Forbrich, J., Krause, M., Dale, J., Borissova, J., and Emerson, J. 2020. "VVV-WIT-01: highly obscured classical nova or protostellar collision?." Monthly Notices of the Royal Astronomical Society 492:4847– 4857. https://doi.org/10.1093/mnras/staa155
ID: 157752
Type: article
Authors: Lucas, P. W.; Minniti, D.; Kamble, Atish; Kaplan, D. L.; Cross, N.; Dekany, I.; Ivanov, V. D.; Kurtev, R.; Saito, R. K.; Smith, L. C.; Catelan, M.; Masetti, N.; Toledo, I.; Hempel, M.; Thompson, M. A.; Contreras Peña, C.; Forbrich, J.; Krause, M.; Dale, J.; Borissova, J.; Emerson, J.
Abstract: A search of the first Data Release of the VISTA Variables in the Via Lactea (VVV) Survey discovered the exceptionally red transient VVV-WIT-01 (H - Ks = 5.2). It peaked before March 2010, then faded by ∼9.5 mag over the following 2 yr. The 1.6-22 μm spectral energy distribution in March 2010 was well fit by a highly obscured blackbody with T ∼ 1000 K and A_{K_s} ∼ 6.6 mag. The source is projected against the Infrared Dark Cloud (IRDC) SDC G331.062-0.294. The chance projection probability is small for any single event (p ≈ 0.01-0.02), which suggests a physical association, e.g. a collision between low mass protostars. However, blackbody emission at T ∼ 1000 K is common in classical novae (especially CO novae) at the infrared peak in the light curve due to condensation of dust ∼30-60 d after the explosion. Radio follow-up with the Australia Telescope Compact Array detected a fading continuum source with properties consistent with a classical nova but probably inconsistent with colliding protostars. Considering all VVV transients that could have been projected against a catalogued IRDC raises the probability of a chance association to p = 0.13-0.24. After weighing several options, it appears likely that VVV-WIT-01 was a classical nova event located behind an IRDC.
Complex Density Wave Orders and Quantum Phase Transitions in a Model of Square-Lattice Rydberg Atom ArraysSamajdar, RhineHo, Wen WeiPichler, HannesLukin, Mikhail D.Sachdev, SubirDOI: info:10.1103/PhysRevLett.124.103601v. 124103601
Samajdar, Rhine, Ho, Wen Wei, Pichler, Hannes, Lukin, Mikhail D., and Sachdev, Subir. 2020. "Complex Density Wave Orders and Quantum Phase Transitions in a Model of Square-Lattice Rydberg Atom Arrays." Physical Review Letters 124:103601. https://doi.org/10.1103/PhysRevLett.124.103601
ID: 157753
Type: article
Authors: Samajdar, Rhine; Ho, Wen Wei; Pichler, Hannes; Lukin, Mikhail D.; Sachdev, Subir
Abstract: We describe the zero-temperature phase diagram of a model of a two-dimensional square-lattice array of neutral atoms, excited into Rydberg states and interacting via strong van der Waals interactions. Using the density-matrix renormalization group algorithm, we map out the phase diagram and obtain a rich variety of phases featuring complex density wave orderings, upon varying lattice spacing and laser detuning. While some of these phases result from the classical optimization of the van der Waals energy, we also find intrinsically quantum-ordered phases stabilized by quantum fluctuations. These phases are surrounded by novel quantum phase transitions, which we analyze by finite-size scaling numerics and Landau theories. Our work highlights Rydberg quantum simulators in higher dimensions as promising platforms to realize exotic many-body phenomena.
Quantum many-body scars from virtual entangled pairsChattopadhyay, SambuddhaPichler, HannesLukin, Mikhail D.Ho, Wen WeiDOI: info:10.1103/PhysRevB.101.174308v. 101174308
Chattopadhyay, Sambuddha, Pichler, Hannes, Lukin, Mikhail D., and Ho, Wen Wei. 2020. "Quantum many-body scars from virtual entangled pairs." Physical Review B 101:174308. https://doi.org/10.1103/PhysRevB.101.174308
ID: 157754
Type: article
Authors: Chattopadhyay, Sambuddha; Pichler, Hannes; Lukin, Mikhail D.; Ho, Wen Wei
Abstract: We study weak ergodicity breaking in a one-dimensional, nonintegrable spin-1 XY model. We construct for it an exact, highly excited eigenstate, which despite its large energy density, can be represented analytically by a finite bond-dimension matrix product state (MPS) with area-law entanglement. Upon a quench to a finite Zeeman field, the state undergoes periodic dynamics with perfect many-body revivals, in stark contrast to other generic initial states which instead rapidly thermalize. This dynamics can be completely understood in terms of the evolution of entangled virtual spin-1/2 degrees of freedom, which in turn underpin the presence of an extensive tower of strong-eigenstate thermalization hypothesis (ETH)-violating many-body eigenstates. The resulting quantum many-body scars are therefore of novel origin. Our results provide important analytical insights into the nature and entanglement structure of quantum many-body scars.
Quantum Approximate Optimization Algorithm: Performance, Mechanism, and Implementation on Near-Term DevicesZhou, LeoWang, Sheng-TaoChoi, SoonwonPichler, HannesLukin, Mikhail D.DOI: info:10.1103/PhysRevX.10.021067v. 10021067
Zhou, Leo, Wang, Sheng-Tao, Choi, Soonwon, Pichler, Hannes, and Lukin, Mikhail D. 2020. "Quantum Approximate Optimization Algorithm: Performance, Mechanism, and Implementation on Near-Term Devices." Physical Review X 10:021067. https://doi.org/10.1103/PhysRevX.10.021067
ID: 157755
Type: article
Authors: Zhou, Leo; Wang, Sheng-Tao; Choi, Soonwon; Pichler, Hannes; Lukin, Mikhail D.
Abstract: The quantum approximate optimization algorithm (QAOA) is a hybrid quantum-classical variational algorithm designed to tackle combinatorial optimization problems. Despite its promise for near-term quantum applications, not much is currently understood about the QAOA's performance beyond its lowest-depth variant. An essential but missing ingredient for understanding and deploying the QAOA is a constructive approach to carry out the outer-loop classical optimization. We provide an in-depth study of the performance of the QAOA on MaxCut problems by developing an efficient parameter-optimization procedure and revealing its ability to exploit nonadiabatic operations. Building on observed patterns in optimal parameters, we propose heuristic strategies for initializing optimizations to find quasioptimal p -level QAOA parameters in O [poly (p )] time, whereas the standard strategy of random initialization requires 2O (p ) optimization runs to achieve similar performance. We then benchmark the QAOA and compare it with quantum annealing, especially on difficult instances where adiabatic quantum annealing fails due to small spectral gaps. The comparison reveals that the QAOA can learn via optimization to utilize nonadiabatic mechanisms to circumvent the challenges associated with vanishing spectral gaps. Finally, we provide a realistic resource analysis on the experimental implementation of the QAOA. When quantum fluctuations in measurements are accounted for, we illustrate that optimization is important only for problem sizes beyond numerical simulations but accessible on near-term devices. We propose a feasible implementation of large MaxCut problems with a few hundred vertices in a system of 2D neutral atoms, reaching the regime to challenge the best classical algorithms.
Author Correction: Quantum metasurfaces with atom arraysBekenstein, RivkaPikovski, IgorPichler, HannesShahmoon, E.Yelin, S. F.Lukin, M. D.DOI: info:10.1038/s41567-020-0912-yv. 16703–703
Bekenstein, Rivka, Pikovski, Igor, Pichler, Hannes, Shahmoon, E., Yelin, S. F., and Lukin, M. D. 2020. "Author Correction: Quantum metasurfaces with atom arrays." Nature Physics 16:703– 703. https://doi.org/10.1038/s41567-020-0912-y
ID: 157756
Type: article
Authors: Bekenstein, Rivka; Pikovski, Igor; Pichler, Hannes; Shahmoon, E.; Yelin, S. F.; Lukin, M. D.
Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper.
One-Way Quantum Repeater Based on Near-Deterministic Photon-Emitter InterfacesBorregaard, JohannesPichler, HannesSchröder, TimLukin, Mikhail D.Lodahl, PeterSørensen, Anders S.DOI: info:10.1103/PhysRevX.10.021071v. 10021071
Borregaard, Johannes, Pichler, Hannes, Schröder, Tim, Lukin, Mikhail D., Lodahl, Peter, and Sørensen, Anders S. 2020. "One-Way Quantum Repeater Based on Near-Deterministic Photon-Emitter Interfaces." Physical Review X 10:021071. https://doi.org/10.1103/PhysRevX.10.021071
ID: 157757
Type: article
Authors: Borregaard, Johannes; Pichler, Hannes; Schröder, Tim; Lukin, Mikhail D.; Lodahl, Peter; Sørensen, Anders S.
Abstract: We propose a novel one-way quantum repeater architecture based on photonic tree-cluster states. Encoding a qubit in a photonic tree cluster protects the information from transmission loss and enables long-range quantum communication through a chain of repeater stations. As opposed to conventional approaches that are limited by the two-way communication time, the overall transmission rate of the current quantum repeater protocol is determined by the local processing time enabling very high communication rates. We further show that such a repeater can be constructed with as little as two stationary qubits and one quantum emitter per repeater station, which significantly increases the experimental feasibility. We discuss potential implementations with diamond defect centers and semiconductor quantum dots efficiently coupled to photonic nanostructures and outline how such systems may be integrated into repeater stations.
Quantum metasurfaces with atom arraysBekenstein, RivkaPikovski, IgorPichler, HannesShahmoon, E.Yelin, S. F.Lukin, M. D.DOI: info:10.1038/s41567-020-0845-5v. 16676–681
Bekenstein, Rivka, Pikovski, Igor, Pichler, Hannes, Shahmoon, E., Yelin, S. F., and Lukin, M. D. 2020. "Quantum metasurfaces with atom arrays." Nature Physics 16:676– 681. https://doi.org/10.1038/s41567-020-0845-5
ID: 157758
Type: article
Authors: Bekenstein, Rivka; Pikovski, Igor; Pichler, Hannes; Shahmoon, E.; Yelin, S. F.; Lukin, M. D.
Abstract: Metasurfaces mould the flow of classical light waves by engineering subwavelength patterns from dielectric or metallic thin films. We introduce and analyse a method in which quantum operator-valued reflectivity can be used to control both the spatiotemporal and quantum properties of transmitted and reflected light. Such quantum metasurfaces are realized by entangling the macroscopic response of atomically thin atom arrays to light. We show that such a system allows for parallel quantum operations between atoms and photons as well as for the generation of highly entangled photonic states such as photonic Greenberger-Horne-Zeilinger and three-dimensional cluster states suitable for quantum information processing. We analyse the influence of imperfections as well as specific implementations based on atom arrays excited into Rydberg states.
Prospects for fundamental physics with LISABarausse, EnricoBerti, EmanueleHertog, ThomasHughes, Scott A.Jetzer, PhilippePani, PaoloSotiriou, Thomas P.Tamanini, NicolaWitek, HelviYagi, KentYunes, NicolásAbdelsalhin, T.Achucarro, A.van Aelst, K.Afshordi, N.Akcay, S.Annulli, L.Arun, K. G.Ayuso, I.Baibhav, V.Baker, T.Bantilan, H.Barreiro, T.Barrera-Hinojosa, C.Bartolo, N.Baumann, D.Belgacem, E.Bellini, E.Bellomo, N.Ben-Dayan, I.Bena, I.Benkel, R.Bergshoefs, E.Bernard, L.Bernuzzi, S.Bertacca, D.Besancon, M.Beutler, F.Beyer, F.Bhagwat, S.Bicak, J.Biondini, S.Bize, S.Blas, D.Boehmer, C.Boller, K.Bonga, B.Bonvin, C.Bosso, P.Bozzola, G.Brax, P.Breitbach, M.Brito, R.Bruni, M.Brügmann, B.Bulten, H.Buonanno, A.Burko, L. M.Burrage, C.Cabral, F.Calcagni, G.Caprini, C.Cárdenas-Avendaño, A.Celoria, M.Chatziioannou, K.Chernoff, D.Clough, K.Coates, A.Comelli, D.Compère, G.Croon, D.Cruces, D.Cusin, G.Dalang, C.Danielsson, U.Das, S.Datta, S.de Boer, J.De Luca, V.De Rham, C.Desjacques, V.Destounis, K.Di Filippo, F.Dima, A.Dimastrogiovanni, E.Dolan, S.Doneva, D.Duque, F.Durrer, R.East, W.Easther, R.Elley, M.Ellis, J. R.Emparan, R.Ezquiaga, J. M.Fairbairn, M.Fairhurst, S.Farmer, H. F.Fasiello, M. R.Ferrari, V.Ferreira, P. G.Ficarra, G.Figueras, P.Fisenko, S.Foffa, S.Franchini, N.Franciolini, G.Fransen, K.Frauendiener, J.Frusciante, N.Fujita, R.Gair, J.Ganz, A.Garcia, P.Garcia-Bellido, J.Garriga, J.Geiger, R.Geng, C.Gergely, L. Á.Germani, C.Gerosa, D.Giddings, S. B.Gourgoulhon, E.Grandclement, P.Graziani, L.Gualtieri, L.Haggard, D.Haino, S.Halburd, R.Han, W. -BHawken, A. J.Hees, A.Heng, I. S.Hennig, J.Herdeiro, C.Hervik, S.Holten, J. v.Hoyle, C. J. D.Hu, Y.Hull, M.Ikeda, T.Isi, M.Jenkins, A.Julié, F.Kajfasz, E.Kalaghatgi, C.Kaloper, N.Kamionkowski, M.Karas, V.Kastha, S.Keresztes, Z.Kidder, L.Kimpson, T.Klein, A.Klioner, S.Kokkotas, K.Kolesova, H.Kolkowitz, S.Kopp, J.Koyama, K.Krishnendu, N. V.Kroon, J. A. V.Kunz, M.Lahav, O.Landragin, A.Lang, R. N.Le Poncin-Lafitte, C.Lemos, J.Li, B.Liberati, S.Liguori, M.Lin, F.Liu, G.Lobo, F. S. N.Loll, R.Lombriser, L.Lovelace, G.Macedo, R. P.Madge, E.Maggio, E.Maggiore, M.Marassi, S.Marcoccia, P.Markakis, C.Martens, W.Martinovic, K.Martins, C. J. A. P.Maselli, A.Mastrogiovanni, S.Matarrese, S.Matas, A.Mavromatos, N. E.Mazumdar, A.Meerburg, P. D.Megias, E.Miller, J.Mimoso, J. P.Mittnacht, L.Montero, M. M.Moore, B.Martin-Moruno, P.Musco, I.Nakano, H.Nampalliwar, S.Nardini, G.Nielsen, A.Novák, J.Nunes, N. J.Okounkova, M.Oliveri, R.Oppizzi, F.Orlando, G.Oshita, N.Pappas, G.Paschalidis, V.Peiris, H.Peloso, M.Perkins, S.Pettorino, V.Pikovski, IgorPilo, L.Podolsky, J.Pontzen, A.Prabhat, S.Pratten, G.Prokopec, T.Prouza, M.Qi, H.Raccanelli, A.Rajantie, A.Randall, L.Raposo, G.Raymond, V.Renaux-Petel, S.Ricciardone, A.Riotto, A.Robson, T.Roest, D.Rollo, R.Rosofsky, S.Ruan, J. J.Rubiera-García, D.Ruiz, M.Rusu, M.Sabatie, F.Sago, N.Sakellariadou, M.Saltas, I. D.Sberna, L.Sathyaprakash, B.Scheel, M.Schmidt, P.Schutz, B.Schwaller, P.Shao, L.Shapiro, S. L.Shoemaker, D.Silva, A. D.Simpson, C.Sopuerta, C. F.Spallicci, A.Stefanek, B. A.Stein, L.Stergioulas, N.Stott, M.Sutton, P.Svarc, R.Tagoshi, H.Tahamtan, T.Takeda, H.Tanaka, T.Tantilian, G.Tasinato, G.Tattersall, O.Teukolsky, S.Tiec, A. L.Theureau, G.Trodden, M.Tolley, A.Toubiana, A.Traykova, D.Tsokaros, A.Unal, C.Unnikrishnan, C. S.Vagenas, E. C.Valageas, P.Vallisneri, M.Van den Brand, J.Van Den Broeck, C.van de Meent, M.Vanhove, P.Varma, V.Veitch, J.Vercnocke, B.Verde, L.Vernieri, D.Vernizzi, F.Vicente, R.Vidotto, F.Visser, M.Vlah, Z.Vretinaris, S.Völkel, S.Wang, Q.Wang, Yu-TongWerner, M. C.Westernacher, J.Weygaert, R. v. d.Wiltshire, D.Wiseman, T.Wolf, P.Wu, K.Yamada, K.Yang, H.Yi, L.Yue, X.Yvon, D.Zilhão, M.Zimmerman, A.Zumalacarregui, M.DOI: info:10.1007/s10714-020-02691-1v. 5281
Barausse, Enrico, Berti, Emanuele, Hertog, Thomas, Hughes, Scott A., Jetzer, Philippe, Pani, Paolo, Sotiriou, Thomas P., Tamanini, Nicola, Witek, Helvi, Yagi, Kent, Yunes, Nicolás, Abdelsalhin, T., Achucarro, A., van Aelst, K., Afshordi, N., Akcay, S., Annulli, L., Arun, K. G., Ayuso, I., Baibhav, V., Baker, T., Bantilan, H., Barreiro, T., Barrera-Hinojosa, C., Bartolo, N. et al. 2020. "Prospects for fundamental physics with LISA." General Relativity and Gravitation 52:81. https://doi.org/10.1007/s10714-020-02691-1
ID: 157759
Type: article
Authors: Barausse, Enrico; Berti, Emanuele; Hertog, Thomas; Hughes, Scott A.; Jetzer, Philippe; Pani, Paolo; Sotiriou, Thomas P.; Tamanini, Nicola; Witek, Helvi; Yagi, Kent; Yunes, Nicolás; Abdelsalhin, T.; Achucarro, A.; van Aelst, K.; Afshordi, N.; Akcay, S.; Annulli, L.; Arun, K. G.; Ayuso, I.; Baibhav, V.; Baker, T.; Bantilan, H.; Barreiro, T.; Barrera-Hinojosa, C.; Bartolo, N.; Baumann, D.; Belgacem, E.; Bellini, E.; Bellomo, N.; Ben-Dayan, I.; Bena, I.; Benkel, R.; Bergshoefs, E.; Bernard, L.; Bernuzzi, S.; Bertacca, D.; Besancon, M.; Beutler, F.; Beyer, F.; Bhagwat, S.; Bicak, J.; Biondini, S.; Bize, S.; Blas, D.; Boehmer, C.; Boller, K.; Bonga, B.; Bonvin, C.; Bosso, P.; Bozzola, G.; Brax, P.; Breitbach, M.; Brito, R.; Bruni, M.; Brügmann, B.; Bulten, H.; Buonanno, A.; Burko, L. M.; Burrage, C.; Cabral, F.; Calcagni, G.; Caprini, C.; Cárdenas-Avendaño, A.; Celoria, M.; Chatziioannou, K.; Chernoff, D.; Clough, K.; Coates, A.; Comelli, D.; Compère, G.; Croon, D.; Cruces, D.; Cusin, G.; Dalang, C.; Danielsson, U.; Das, S.; Datta, S.; de Boer, J.; De Luca, V.; De Rham, C.; Desjacques, V.; Destounis, K.; Di Filippo, F.; Dima, A.; Dimastrogiovanni, E.; Dolan, S.; Doneva, D.; Duque, F.; Durrer, R.; East, W.; Easther, R.; Elley, M.; Ellis, J. R.; Emparan, R.; Ezquiaga, J. M.; Fairbairn, M.; Fairhurst, S.; Farmer, H. F.; Fasiello, M. R.; Ferrari, V.; Ferreira, P. G.; Ficarra, G.; Figueras, P.; Fisenko, S.; Foffa, S.; Franchini, N.; Franciolini, G.; Fransen, K.; Frauendiener, J.; Frusciante, N.; Fujita, R.; Gair, J.; Ganz, A.; Garcia, P.; Garcia-Bellido, J.; Garriga, J.; Geiger, R.; Geng, C.; Gergely, L. Á.; Germani, C.; Gerosa, D.; Giddings, S. B.; Gourgoulhon, E.; Grandclement, P.; Graziani, L.; Gualtieri, L.; Haggard, D.; Haino, S.; Halburd, R.; Han, W. -B; Hawken, A. J.; Hees, A.; Heng, I. S.; Hennig, J.; Herdeiro, C.; Hervik, S.; Holten, J. v.; Hoyle, C. J. D.; Hu, Y.; Hull, M.; Ikeda, T.; Isi, M.; Jenkins, A.; Julié, F.; Kajfasz, E.; Kalaghatgi, C.; Kaloper, N.; Kamionkowski, M.; Karas, V.; Kastha, S.; Keresztes, Z.; Kidder, L.; Kimpson, T.; Klein, A.; Klioner, S.; Kokkotas, K.; Kolesova, H.; Kolkowitz, S.; Kopp, J.; Koyama, K.; Krishnendu, N. V.; Kroon, J. A. V.; Kunz, M.; Lahav, O.; Landragin, A.; Lang, R. N.; Le Poncin-Lafitte, C.; Lemos, J.; Li, B.; Liberati, S.; Liguori, M.; Lin, F.; Liu, G.; Lobo, F. S. N.; Loll, R.; Lombriser, L.; Lovelace, G.; Macedo, R. P.; Madge, E.; Maggio, E.; Maggiore, M.; Marassi, S.; Marcoccia, P.; Markakis, C.; Martens, W.; Martinovic, K.; Martins, C. J. A. P.; Maselli, A.; Mastrogiovanni, S.; Matarrese, S.; Matas, A.; Mavromatos, N. E.; Mazumdar, A.; Meerburg, P. D.; Megias, E.; Miller, J.; Mimoso, J. P.; Mittnacht, L.; Montero, M. M.; Moore, B.; Martin-Moruno, P.; Musco, I.; Nakano, H.; Nampalliwar, S.; Nardini, G.; Nielsen, A.; Novák, J.; Nunes, N. J.; Okounkova, M.; Oliveri, R.; Oppizzi, F.; Orlando, G.; Oshita, N.; Pappas, G.; Paschalidis, V.; Peiris, H.; Peloso, M.; Perkins, S.; Pettorino, V.; Pikovski, Igor; Pilo, L.; Podolsky, J.; Pontzen, A.; Prabhat, S.; Pratten, G.; Prokopec, T.; Prouza, M.; Qi, H.; Raccanelli, A.; Rajantie, A.; Randall, L.; Raposo, G.; Raymond, V.; Renaux-Petel, S.; Ricciardone, A.; Riotto, A.; Robson, T.; Roest, D.; Rollo, R.; Rosofsky, S.; Ruan, J. J.; Rubiera-García, D.; Ruiz, M.; Rusu, M.; Sabatie, F.; Sago, N.; Sakellariadou, M.; Saltas, I. D.; Sberna, L.; Sathyaprakash, B.; Scheel, M.; Schmidt, P.; Schutz, B.; Schwaller, P.; Shao, L.; Shapiro, S. L.; Shoemaker, D.; Silva, A. D.; Simpson, C.; Sopuerta, C. F.; Spallicci, A.; Stefanek, B. A.; Stein, L.; Stergioulas, N.; Stott, M.; Sutton, P.; Svarc, R.; Tagoshi, H.; Tahamtan, T.; Takeda, H.; Tanaka, T.; Tantilian, G.; Tasinato, G.; Tattersall, O.; Teukolsky, S.; Tiec, A. L.; Theureau, G.; Trodden, M.; Tolley, A.; Toubiana, A.; Traykova, D.; Tsokaros, A.; Unal, C.; Unnikrishnan, C. S.; Vagenas, E. C.; Valageas, P.; Vallisneri, M.; Van den Brand, J.; Van Den Broeck, C.; van de Meent, M.; Vanhove, P.; Varma, V.; Veitch, J.; Vercnocke, B.; Verde, L.; Vernieri, D.; Vernizzi, F.; Vicente, R.; Vidotto, F.; Visser, M.; Vlah, Z.; Vretinaris, S.; Völkel, S.; Wang, Q.; Wang, Yu-Tong; Werner, M. C.; Westernacher, J.; Weygaert, R. v. d.; Wiltshire, D.; Wiseman, T.; Wolf, P.; Wu, K.; Yamada, K.; Yang, H.; Yi, L.; Yue, X.; Yvon, D.; Zilhão, M.; Zimmerman, A.; Zumalacarregui, M.
Abstract: In this paper, which is of programmatic rather than quantitative nature, we aim to further delineate and sharpen the future potential of the LISA mission in the area of fundamental physics. Given the very broad range of topics that might be relevant to LISA,we present here a sample of what we view as particularly promising fundamental physics directions. We organize these directions through a "science-first" approach that allows us to classify how LISA data can inform theoretical physics in a variety of areas. For each of these theoretical physics classes, we identify the sources that are currently expected to provide the principal contribution to our knowledge, and the areas that need further development. The classification presented here should not be thought of as cast in stone, but rather as a fluid framework that is amenable to change with the flow of new insights in theoretical physics.
Phase-modulated X-Ray Emission from Cepheids due to Pulsation-driven ShocksMoschou, Sofia-ParaskeviVlahakis, NektariosDrake, Jeremy J.Evans, Nancy RemageNeilson, Hilding R.Guzik, Joyce AnnZuhone, JohnDOI: info:10.3847/1538-4357/aba8fav. 900157
Moschou, Sofia-Paraskevi, Vlahakis, Nektarios, Drake, Jeremy J., Evans, Nancy Remage, Neilson, Hilding R., Guzik, Joyce Ann, and Zuhone, John. 2020. "Phase-modulated X-Ray Emission from Cepheids due to Pulsation-driven Shocks." The Astrophysical Journal 900:157. https://doi.org/10.3847/1538-4357/aba8fa
ID: 157760
Type: article
Authors: Moschou, Sofia-Paraskevi; Vlahakis, Nektarios; Drake, Jeremy J.; Evans, Nancy Remage; Neilson, Hilding R.; Guzik, Joyce Ann; Zuhone, John
Abstract: Cepheids are pulsating variable stars with a periodic chromospheric response at UV wavelengths close to their minimum radius phase. Recently, an X-ray variable signature was captured in observations during the maximum radius phase. This X-ray emission came as a surprise and is not understood. In this work, we use the modern astrophysical code PLUTO to investigate the effects of pulsations on Cepheid X-ray emission. We run a number of hydrodynamic numerical simulations with a variety of initial and boundary conditions in order to explore the capability of shocks to produce the observed phase-dependent X-ray behavior. Finally, we use the Simulated Observations of X-ray Sources (SOXS) package to create synthetic spectra for each simulation case and link our simulations to observables. We show that, for certain conditions, we can reproduce observed X-ray fluxes at phases 0.4-0.8 when the Cepheid is at maximum radius. Our results span a wide range of mass-loss rates, 2 × 10-13 M yr-1 to 3 × 10-8 M yr-1, and peak X-ray luminosities, 5 × 10-17 erg cm-2 s-1 to 1.4 × 10-12 erg cm-2 s-1. We conclude that Cepheids exhibit two-component emission with (a) shock waves being responsible for the phase-dependent variable emission (phases 0.2-0.6) and (b) a separate quiescent mechanism being the dominant emission mechanism for the remaining phases.
The Space Environment and Atmospheric Joule Heating of the Habitable Zone Exoplanet TOI 700 dCohen, OferGarraffo, CeciliaMoschou, Sofia-ParaskeviDrake, Jeremy J.Alvarado-Gómez, J. D.Glocer, AlexFraschetti, FedericoDOI: info:10.3847/1538-4357/ab9637v. 897101
Cohen, Ofer, Garraffo, Cecilia, Moschou, Sofia-Paraskevi, Drake, Jeremy J., Alvarado-Gómez, J. D., Glocer, Alex, and Fraschetti, Federico. 2020. "The Space Environment and Atmospheric Joule Heating of the Habitable Zone Exoplanet TOI 700 d." The Astrophysical Journal 897:101. https://doi.org/10.3847/1538-4357/ab9637
ID: 157761
Type: article
Authors: Cohen, Ofer; Garraffo, Cecilia; Moschou, Sofia-Paraskevi; Drake, Jeremy J.; Alvarado-Gómez, J. D.; Glocer, Alex; Fraschetti, Federico
Abstract: We investigate the space environment conditions near the Earth-size planet TOI 700 d using a set of numerical models for the stellar corona and wind, the planetary magnetosphere, and the planetary ionosphere. We drive our simulations using a scaled-down stellar input and a scaled-up solar input in order to obtain two independent solutions. We find that for the particular parameters used in our study, the stellar wind conditions near the planet are not very extreme-slightly stronger than that near the Earth in terms of the stellar wind ram pressure and the intensity of the interplanetary magnetic field. Thus, the space environment near TOI 700 d may not be extremely harmful to the planetary atmosphere, assuming the planet resembles the Earth. Nevertheless, we stress that the stellar input parameters and the actual planetary parameters are unconstrained, and different parameters may result in a much greater effect on the atmosphere of TOI 700 d. Finally, we compare our results to solar wind measurements in the solar system and stress that modest stellar wind conditions may not guarantee atmospheric retention of exoplanets.
Atmospheric Escape Processes and Planetary Atmospheric EvolutionGronoff, G.Arras, P.Baraka, S.Bell, J. M.Cessateur, G.Cohen, O.Curry, S. M.Drake, Jeremy J.Elrod, M.Erwin, J.Garcia-Sage, K.Garraffo, CeciliaGlocer, A.Heavens, N. G.Lovato, K.Maggiolo, R.Parkinson, C. D.Simon Wedlund, C.Weimer, D. R.Moore, W. B.DOI: info:10.1029/2019JA027639v. 125e27639
Gronoff, G., Arras, P., Baraka, S., Bell, J. M., Cessateur, G., Cohen, O., Curry, S. M., Drake, Jeremy J., Elrod, M., Erwin, J., Garcia-Sage, K., Garraffo, Cecilia, Glocer, A., Heavens, N. G., Lovato, K., Maggiolo, R., Parkinson, C. D., Simon Wedlund, C., Weimer, D. R., and Moore, W. B. 2020. "Atmospheric Escape Processes and Planetary Atmospheric Evolution." Journal of Geophysical Research (Space Physics) 125:e27639. https://doi.org/10.1029/2019JA027639
ID: 157762
Type: article
Authors: Gronoff, G.; Arras, P.; Baraka, S.; Bell, J. M.; Cessateur, G.; Cohen, O.; Curry, S. M.; Drake, Jeremy J.; Elrod, M.; Erwin, J.; Garcia-Sage, K.; Garraffo, Cecilia; Glocer, A.; Heavens, N. G.; Lovato, K.; Maggiolo, R.; Parkinson, C. D.; Simon Wedlund, C.; Weimer, D. R.; Moore, W. B.
Abstract: The habitability of the surface of any planet is determined by a complex evolution of its interior, surface, and atmosphere. The electromagnetic and particle radiation of stars drive thermal, chemical, and physical alteration of planetary atmospheres, including escape. Many known extrasolar planets experience vastly different stellar environments than those in our solar system: It is crucial to understand the broad range of processes that lead to atmospheric escape and evolution under a wide range of conditions if we are to assess the habitability of worlds around other stars. One problem encountered between the planetary and the astrophysics communities is a lack of common language for describing escape processes. Each community has customary approximations that may be questioned by the other, such as the hypothesis of H-dominated thermosphere for astrophysicists or the Sun-like nature of the stars for planetary scientists. Since exoplanets are becoming one of the main targets for the detection of life, a common set of definitions and hypotheses are required. We review the different escape mechanisms proposed for the evolution of planetary and exoplanetary atmospheres. We propose a common definition for the different escape mechanisms, and we show the important parameters to take into account when evaluating the escape at a planet in time. We show that the paradigm of the magnetic field as an atmospheric shield should be changed and that recent work on the history of Xenon in Earth's atmosphere gives an elegant explanation to its enrichment in heavier isotopes: the so-called Xenon paradox.
The Family of Amide Molecules toward NGC 6334ILigterink, Niels F. W.El-Abd, Samer J.Brogan, Crystal L.Hunter, Todd R.Remijan, Anthony J.Garrod, Robin T.McGuire, BrettDOI: info:10.3847/1538-4357/abad38v. 90137
Ligterink, Niels F. W., El-Abd, Samer J., Brogan, Crystal L., Hunter, Todd R., Remijan, Anthony J., Garrod, Robin T., and McGuire, Brett. 2020. "The Family of Amide Molecules toward NGC 6334I." The Astrophysical Journal 901:37. https://doi.org/10.3847/1538-4357/abad38
ID: 157763
Type: article
Authors: Ligterink, Niels F. W.; El-Abd, Samer J.; Brogan, Crystal L.; Hunter, Todd R.; Remijan, Anthony J.; Garrod, Robin T.; McGuire, Brett
Abstract: Amide molecules produced in space could play a key role in the formation of biomolecules on a young planetary object. However, the formation and chemical network of amide molecules in space is not well understood. In this work, Atacama Large Millimeter/submillimeter Array observations are used to study a number of amide(-like) molecules toward the high-mass star-forming region NGC 6334I. The first detections of cyanamide (NH2CN), acetamide (CH3C(O)NH2), and N-methylformamide (CH3NHCHO) are presented for this source. These are combined with analyses of isocyanic acid (HNCO) and formamide (NH2CHO), and a tentative detection of urea (carbamide; NH2C(O)NH2). Abundance correlations show that most amides are likely formed in related reactions occurring in ices on interstellar dust grains in NGC 6334I. However, in an expanded sample of sources, large abundance variations are seen for NH2CN that seem to depend on the source type, which suggests that the physical conditions within the source heavily influence the production of this species. The rich amide inventory of NGC 6334I strengthens the case that interstellar molecules can contribute to the emergence of biomolecules on planets.
The White Dwarf Opportunity: Robust Detections of Molecules in Earth-like Exoplanet Atmospheres with the James Webb Space TelescopeKaltenegger, LisaMacDonald, Ryan J.Kozakis, TheaLewis, Nikole K.Mamajek, Eric E.McDowell, Jonathan C.Vanderburg, AndrewDOI: info:10.3847/2041-8213/aba9d3v. 901L1
Kaltenegger, Lisa, MacDonald, Ryan J., Kozakis, Thea, Lewis, Nikole K., Mamajek, Eric E., McDowell, Jonathan C., and Vanderburg, Andrew. 2020. "The White Dwarf Opportunity: Robust Detections of Molecules in Earth-like Exoplanet Atmospheres with the James Webb Space Telescope." The Astrophysical Journal 901:L1. https://doi.org/10.3847/2041-8213/aba9d3
ID: 157764
Type: article
Authors: Kaltenegger, Lisa; MacDonald, Ryan J.; Kozakis, Thea; Lewis, Nikole K.; Mamajek, Eric E.; McDowell, Jonathan C.; Vanderburg, Andrew
Abstract: The near-term search for life beyond the solar system currently focuses on transiting planets orbiting small M dwarfs, and the challenges of detecting signs of life in their atmospheres. However, planets orbiting white dwarfs (WDs) would provide a unique opportunity to characterize rocky worlds. The discovery of the first transiting giant planet orbiting a WD, WD 1856+534, showed that planetary-mass objects can survive close-in orbits around WDs. The large radius ratio between WD planets and their host renders them exceptional targets for transmission spectroscopy. Here, we explore the molecular detectability and atmospheric characterization potential for a notional Earth-like planet, evolving in the habitable zone of WD 1856+534, with the James Webb Space Telescope (JWST). We establish that the atmospheric composition of such Earth-like planets orbiting WDs can be precisely retrieved with JWST. We demonstrate that robust >5σ detections of H2O and CO2 can be achieved in a five-transit reconnaissance program, while the biosignatures O3 + CH4 and CH4 + N2O can be detected to >4σ in as few as 25 transits. N2 and O2 can be detected to >5σ within 100 transits. Given the short transit duration of WD habitable zone planets (∼2 minutes for WD 1856+534), conclusive molecular detections can be achieved in a small or medium JWST transmission spectroscopy program. Rocky planets in the WD habitable zone therefore represent a promising opportunity to characterize terrestrial planet atmospheres and explore the possibility of a second genesis on these worlds.
The Megamaser Cosmology Project - XII. VLBI imaging of H2O maser emission in three active galaxies and the effect of AGN winds on disc dynamicsKuo, C. Y.Braatz, J. A.Impellizzeri, C. M. V.Gao, F.Pesce, Dominic W.Reid, Mark J.Condon, J.Kamali, F.Henkel, C.Greene, J. E.DOI: info:10.1093/mnras/staa2260v. 4981609–1627
Kuo, C. Y., Braatz, J. A., Impellizzeri, C. M. V., Gao, F., Pesce, Dominic W., Reid, Mark J., Condon, J., Kamali, F., Henkel, C., and Greene, J. E. 2020. "The Megamaser Cosmology Project - XII. VLBI imaging of H2O maser emission in three active galaxies and the effect of AGN winds on disc dynamics." Monthly Notices of the Royal Astronomical Society 498:1609– 1627. https://doi.org/10.1093/mnras/staa2260
ID: 157765
Type: article
Authors: Kuo, C. Y.; Braatz, J. A.; Impellizzeri, C. M. V.; Gao, F.; Pesce, Dominic W.; Reid, Mark J.; Condon, J.; Kamali, F.; Henkel, C.; Greene, J. E.
Abstract: We present very long baseline interferometry (VLBI) images and kinematics of water maser emission in three active galaxies: NGC 5728, Mrk 1, and IRAS 08452-0011. IRAS 08452-0011, at a distance of ∼200 Mpc, is a triple-peaked H2O megamaser, consistent with a Keplerian rotating disc, indicating a black hole mass of (3.3 $\pm 0.2)\times 10^{7}\, \mathrm{ M}_{\odot }$ . NGC 5728 and Mrk 1 display double-peaked spectra, and VLBI imaging reveals complicated gas kinematics that do not allow for a robust determination of black hole mass. We show evidence that the masers in NGC 5728 are in a wind while the Mrk 1 maser system has both disc and outflow components. We also find that disturbed morphology and kinematics are a ubiquitous feature of all double-peaked maser systems, implying that these maser sources may reside in environments where active galactic nucleus (AGN) winds are prominent at ∼1 pc scale and have significant impact on the masing gas. Such AGNs tend to have black hole masses $M_{\rm BH}\, \lt$ 8 × 106 M and Eddington ratios $\lambda _{\rm Edd}\, \gtrsim$ 0.1, while the triple-peaked megamasers show an opposite trend.
Hybrid Very Long Baseline Interferometry Imaging and Modeling with THEMISBroderick, Avery E.Pesce, Dominic W.Tiede, PaulPu, Hung-YiGold, RomanDOI: info:10.3847/1538-4357/ab9c1fv. 8989
Broderick, Avery E., Pesce, Dominic W., Tiede, Paul, Pu, Hung-Yi, and Gold, Roman. 2020. "Hybrid Very Long Baseline Interferometry Imaging and Modeling with THEMIS." The Astrophysical Journal 898:9. https://doi.org/10.3847/1538-4357/ab9c1f
ID: 157766
Type: article
Authors: Broderick, Avery E.; Pesce, Dominic W.; Tiede, Paul; Pu, Hung-Yi; Gold, Roman
Abstract: Generating images from very long baseline interferometric observations poses a difficult, and generally not unique, inversion problem. This problem is simplified by the introduction of constraints, some generic (e.g., positivity of the intensity) and others motivated by physical considerations (e.g., smoothness, instrument resolution). It is further complicated by the need to simultaneously address instrumental systematic uncertainties and sparse coverage in the u-v plane. We report a new Bayesian image reconstruction technique in the parameter estimation framework THEMIS that has been developed for the Event Horizon Telescope. This has two key features: first, the full Bayesian treatment of the image reconstruction makes it possible to generate a full posterior for the images, permitting a rigorous and quantitative investigation into the statistical significance of image features. Second, it is possible to seamlessly incorporate directly modeled features simultaneously with image reconstruction. We demonstrate this second capability by incorporating a narrow, slashed ring in reconstructions of simulated M87 data in an attempt to detect and characterize the photon ring. We show that it is possible to obtain high-fidelity photon ring sizes, enabling mass measurements with accuracies of 2%-5% that are essentially insensitive to astrophysical uncertainties, and creating opportunities for precision tests of general relativity.
Dynamical Masses for the Pleiades Binary System HII-2147Torres, GuillermoMelis, CarlKraus, Adam L.Dupuy, Trent J.Chilcote, Jeffrey K.Crepp, Justin R.DOI: info:10.3847/1538-4357/ab9c20v. 8982
Torres, Guillermo, Melis, Carl, Kraus, Adam L., Dupuy, Trent J., Chilcote, Jeffrey K., and Crepp, Justin R. 2020. "Dynamical Masses for the Pleiades Binary System HII-2147." The Astrophysical Journal 898:2. https://doi.org/10.3847/1538-4357/ab9c20
ID: 157767
Type: article
Authors: Torres, Guillermo; Melis, Carl; Kraus, Adam L.; Dupuy, Trent J.; Chilcote, Jeffrey K.; Crepp, Justin R.
Abstract: We report our long-term spectroscopic monitoring of the Pleiades member HII-2147, which was previously spatially resolved at radio wavelengths in very long baseline interferometry (VLBI) observations. It has also been claimed to be a (presumably short-period) double-lined spectroscopic binary with relatively sharp lines, although no orbit has ever been published. Examination of our new spectroscopic material and the historical radial velocities shows that the current and previous spectra are best interpreted as featuring only a single set of lines of a moderately rapidly rotating star with slowly variable radial velocity, which is one of the sources detected by VLBI. We combine our own and other velocities with the VLBI measurements and new adaptive optics observations to derive the first astrometric-spectroscopic orbit of the G5 + G9 pair, with a period of 18.18 ± 0.11 yr. We infer dynamical masses of 0.897 ± 0.022 M for the spectroscopically visible star and 0.978 ± 0.024 M for the other, along with a distance of ${136.78}_{-0.46}^{+0.50}$ pc. The lack of detection of the lines of the more massive component in our spectra can be adequately explained if it is rotating much more rapidly than the star we see. This is consistent with the observation that the lines of the secondary are shallower than expected for a star of its spectral type.
The TESS light curve of AI PhoenicisMaxted, P. F. L.Gaulme, PatrickGraczyk, D.Hełminiak, K. G.Johnston, C.Orosz, Jerome A.Prša, AndrejSouthworth, JohnTorres, GuillermoDavies, Guy R.Ball, WarrickChaplin, William J.DOI: info:10.1093/mnras/staa1662v. 498332–343
Maxted, P. F. L., Gaulme, Patrick, Graczyk, D., Hełminiak, K. G., Johnston, C., Orosz, Jerome A., Prša, Andrej, Southworth, John, Torres, Guillermo, Davies, Guy R., Ball, Warrick, and Chaplin, William J. 2020. "The TESS light curve of AI Phoenicis." Monthly Notices of the Royal Astronomical Society 498:332– 343. https://doi.org/10.1093/mnras/staa1662
ID: 157768
Type: article
Authors: Maxted, P. F. L.; Gaulme, Patrick; Graczyk, D.; Hełminiak, K. G.; Johnston, C.; Orosz, Jerome A.; Prša, Andrej; Southworth, John; Torres, Guillermo; Davies, Guy R.; Ball, Warrick; Chaplin, William J.
Abstract: Accurate masses and radii for normal stars derived from observations of detached eclipsing binary stars are of fundamental importance for testing stellar models and may be useful for calibrating free parameters in these model if the masses and radii are sufficiently precise and accurate. We aim to measure precise masses and radii for the stars in the bright eclipsing binary AI Phe, and to quantify the level of systematic error in these estimates. We use several different methods to model the Transiting Exoplanet Survey Satellite (TESS) light curve of AI Phe combined with spectroscopic orbits from multiple sources to estimate precisely the stellar masses and radii together with robust error estimates. We find that the agreement between different methods for the light-curve analysis is very good but some methods underestimate the errors on the model parameters. The semi-amplitudes of the spectroscopic orbits derived from spectra obtained with modern échelle spectrographs are consistent to within 0.1 per cent. The masses of the stars in AI Phe are $M_1 = 1.1938 \pm 0.0008\, \rm M_{\odot }$ and $M_2 = 1.2438 \pm 0.0008\, \rm M_{\odot }$ , and the radii are $R_1 = 1.8050 \pm 0.0022\, \rm R_{\odot }$ and $R_2 = 2.9332 \pm 0.0023\, \rm R_{\odot }$ . We conclude that it is possible to measure accurate masses and radii for stars in bright eclipsing binary stars to a precision of 0.2 per cent or better using photometry from TESS and spectroscopy obtained with modern échelle spectrographs. We provide recommendations for publishing masses and radii of eclipsing binary stars at this level of precision.
Eclipsing Binaries in the Open Cluster Ruprecht 147. III. The Triple System EPIC 219552514 at the Main-sequence TurnoffTorres, GuillermoVanderburg, AndrewCurtis, Jason L.Kraus, Adam L.Rizzuto, Aaron C.Ireland, Michael J.DOI: info:10.3847/1538-4357/ab911bv. 896162
Torres, Guillermo, Vanderburg, Andrew, Curtis, Jason L., Kraus, Adam L., Rizzuto, Aaron C., and Ireland, Michael J. 2020. "Eclipsing Binaries in the Open Cluster Ruprecht 147. III. The Triple System EPIC 219552514 at the Main-sequence Turnoff." The Astrophysical Journal 896:162. https://doi.org/10.3847/1538-4357/ab911b
ID: 157769
Type: article
Authors: Torres, Guillermo; Vanderburg, Andrew; Curtis, Jason L.; Kraus, Adam L.; Rizzuto, Aaron C.; Ireland, Michael J.
Abstract: Spectroscopic observations are reported for the 2.75 day, double-lined, detached eclipsing binary EPIC 219552514 located at the turnoff of the old nearby open cluster Ruprecht 147. A joint analysis of our radial-velocity measurements and the K2 light curve leads to masses of ${M}_{1}={1.509}_{-0.056}^{+0.063}\,{M}_{\odot }$ and ${M}_{2}={0.649}_{-0.014}^{+0.015}\,{M}_{\odot }$ for the primary and secondary, along with radii of ${R}_{1}={2.505}_{-0.031}^{+0.026}\,{R}_{\odot }$ and ${R}_{2}={0.652}_{-0.012}^{+0.013}\,{R}_{\odot }$ , respectively. The effective temperatures are 6180 ± 100 K for the F7 primary and 4010 ± 170 K for the late K secondary. The orbit is circular, and the stars' rotation appears to be synchronized with the orbital motion. This is the third eclipsing system analyzed in the same cluster, following our earlier studies of EPIC 219394517 and EPIC 219568666. By comparison with stellar evolution models from the PARSEC series, we infer an age of ${2.67}_{-0.55}^{+0.39}$ Gyr that is consistent with the estimates for the other two systems. EPIC 219552514 is a hierarchical triple system, with the period of the slightly eccentric outer orbit being 463 days. The unseen tertiary is either a low-mass M dwarf or a white dwarf.
TESS Reveals a Short-period Sub-Neptune Sibling (HD 86226c) to a Known Long-period Giant PlanetTeske, JohannaDíaz, Matías R.Luque, RafaelMočnik, TeoSeidel, Julia V.Otegi, Jon FernándezFeng, FaboJenkins, James S.Pallè, EnricSégransan, DamienUdry, StèphaneCollins, Karen A.Eastman, Jason D.Ricker, George R.Vanderspek, RolandLatham, David W.Seager, SaraWinn, Joshua N.Jenkins, Jon M.Anderson, David R.Barclay, ThomasBouchy, FrançoisBurt, Jennifer A.Butler, R. PaulCaldwell, Douglas A.Collins, Kevin I.Crane, Jeffrey D.Dorn, CarolineFlowers, ErinHaldemann, JonasHelled, RavitHellier, CoelJensen, Eric L. N.Kane, Stephen R.Law, NicholasLissauer, Jack J.Mann, Andrew W.Marmier, MaximeNielsen, Louise DyregaardRose, Mark E.Shectman, Stephen A.Shporer, AviTorres, GuillermoWang, Sharon X.Wolfgang, AngieWong, IanZiegler, CarlDOI: info:10.3847/1538-3881/ab9f95v. 16096
Teske, Johanna, Díaz, Matías R., Luque, Rafael, Močnik, Teo, Seidel, Julia V., Otegi, Jon Fernández, Feng, Fabo, Jenkins, James S., Pallè, Enric, Ségransan, Damien, Udry, Stèphane, Collins, Karen A., Eastman, Jason D., Ricker, George R., Vanderspek, Roland, Latham, David W., Seager, Sara, Winn, Joshua N., Jenkins, Jon M., Anderson, David R., Barclay, Thomas, Bouchy, François, Burt, Jennifer A., Butler, R. Paul, Caldwell, Douglas A. et al. 2020. "TESS Reveals a Short-period Sub-Neptune Sibling (HD 86226c) to a Known Long-period Giant Planet." The Astronomical Journal 160:96. https://doi.org/10.3847/1538-3881/ab9f95
ID: 157770
Type: article
Authors: Teske, Johanna; Díaz, Matías R.; Luque, Rafael; Močnik, Teo; Seidel, Julia V.; Otegi, Jon Fernández; Feng, Fabo; Jenkins, James S.; Pallè, Enric; Ségransan, Damien; Udry, Stèphane; Collins, Karen A.; Eastman, Jason D.; Ricker, George R.; Vanderspek, Roland; Latham, David W.; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Anderson, David R.; Barclay, Thomas; Bouchy, François; Burt, Jennifer A.; Butler, R. Paul; Caldwell, Douglas A.; Collins, Kevin I.; Crane, Jeffrey D.; Dorn, Caroline; Flowers, Erin; Haldemann, Jonas; Helled, Ravit; Hellier, Coel; Jensen, Eric L. N.; Kane, Stephen R.; Law, Nicholas; Lissauer, Jack J.; Mann, Andrew W.; Marmier, Maxime; Nielsen, Louise Dyregaard; Rose, Mark E.; Shectman, Stephen A.; Shporer, Avi; Torres, Guillermo; Wang, Sharon X.; Wolfgang, Angie; Wong, Ian; Ziegler, Carl
Abstract: The Transiting Exoplanet Survey Satellite mission was designed to find transiting planets around bright, nearby stars. Here, we present the detection and mass measurement of a small, short-period (≍4 days) transiting planet around the bright (V = 7.9), solar-type star HD 86226 (TOI-652, TIC 22221375), previously known to host a long-period (∼1600 days) giant planet. HD 86226c (TOI-652.01) has a radius of 2.16 ± 0.08 R and a mass of ${7.25}_{-1.12}^{+1.19}$ M, based on archival and new radial velocity data. We also update the parameters of the longer-period, not-known-to-transit planet, and find it to be less eccentric and less massive than previously reported. The density of the transiting planet is 3.97 g cm-3, which is low enough to suggest that the planet has at least a small volatile envelope, but the mass fractions of rock, iron, and water are not well-constrained. Given the host star brightness, planet period, and location of the planet near both the "radius gap" and the "hot Neptune desert," HD 86226c is an interesting candidate for transmission spectroscopy to further refine its composition. * This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.
PTFO 8-8695: Two Stars, Two Signals, No PlanetBouma, L. G.Winn, J. N.Ricker, G. R.Vanderspek, R.Latham, David W.Seager, S.Jenkins, J. M.Barclay, T.Collins, Karen A.Doty, J. P.Louie, D. R.Quinn, Samuel N.Rose, M. E.Smith, J. C.Villaseñor, J.Wohler, B.DOI: info:10.3847/1538-3881/ab9e73v. 16086
Bouma, L. G., Winn, J. N., Ricker, G. R., Vanderspek, R., Latham, David W., Seager, S., Jenkins, J. M., Barclay, T., Collins, Karen A., Doty, J. P., Louie, D. R., Quinn, Samuel N., Rose, M. E., Smith, J. C., Villaseñor, J., and Wohler, B. 2020. "PTFO 8-8695: Two Stars, Two Signals, No Planet." The Astronomical Journal 160:86. https://doi.org/10.3847/1538-3881/ab9e73
ID: 157771
Type: article
Authors: Bouma, L. G.; Winn, J. N.; Ricker, G. R.; Vanderspek, R.; Latham, David W.; Seager, S.; Jenkins, J. M.; Barclay, T.; Collins, Karen A.; Doty, J. P.; Louie, D. R.; Quinn, Samuel N.; Rose, M. E.; Smith, J. C.; Villaseñor, J.; Wohler, B.
Abstract: PTFO 8-8695 (CVSO 30) is a star in the 7-10 million year old Orion OB1a cluster that shows brightness dips that resemble planetary transits. Although strong evidence against the planet hypothesis has been presented, the possibility remains debated in the literature. To obtain further clues, we inspected data from the NASA Transiting Exoplanet Survey Satellite (TESS) and the ESA Gaia mission. The Gaia data suggest that PTFO 8-8695 is a binary: the photometric data show it to be overluminous with respect to members of its kinematic group, and the astrometric data are inconsistent with a single star. The TESS light curve shows two different photometric periods. The variability is dominated by a sinusoidal signal with a period of 11.98 hr, presumably caused by stellar rotation. Also present is a 10.76 hr signal consisting of a not-quite sinusoid interrupted by hour-long dips, the type of signal previously interpreted as planetary transits. The phase of the dips is nearly 180° away from the phase of the originally reported dips. As noted previously, this makes them difficult to explain as planetary transits. Instead, we believe that PTFO 8-8695 is a pair of young and rapidly rotating M dwarfs, one of which shows the same "transient-dipper" behavior that has been seen in at least five other cases. The origin of these transient dips is still unknown but likely involves circumstellar material.
Three short-period Jupiters from TESS. HIP 65Ab, TOI-157b, and TOI-169bNielsen, L. D.Brahm, R.Bouchy, F.Espinoza, N.Turner, O.Rappaport, S.Pearce, L.Ricker, G.Vanderspek, R.Latham, David W.Seager, S.Winn, J. N.Jenkins, J. M.Acton, J. S.Bakos, G.Barclay, T.Barkaoui, K.Bhatti, W.Briceño, C.Bryant, E. M.Burleigh, M. R.Ciardi, D. R.Collins, K. A.Collins, K. I.Cooke, B. F.Csubry, Z.dos Santos, L. A.Eigmüller, PhFausnaugh, M. M.Gan, T.Gillon, M.Goad, M. R.Guerrero, N.Hagelberg, J.Hart, R.Henning, T.Huang, C. X.Jehin, E.Jenkins, J. S.Jordán, A.Kielkopf, J. F.Kossakowski, D.Lavie, B.Law, N.Lendl, M.de Leon, J. P.Lovis, C.Mann, A. W.Marmier, M.McCormac, J.Mori, M.Moyano, M.Narita, N.Osip, D.Otegi, J. F.Pepe, F.Pozuelos, F. J.Raynard, L.Relles, Howard M.Sarkis, P.Ségransan, D.Seidel, J. V.Shporer, A.Stalport, M.Stockdale, C.Suc, V.Tamura, M.Tan, T. G.Tilbrook, R. H.Ting, E. B.Trifonov, T.Udry, S.Vanderburg, A.Wheatley, P. J.Wingham, G.Zhan, Z.Ziegler, C.DOI: info:10.1051/0004-6361/202037941v. 639A76
Nielsen, L. D., Brahm, R., Bouchy, F., Espinoza, N., Turner, O., Rappaport, S., Pearce, L., Ricker, G., Vanderspek, R., Latham, David W., Seager, S., Winn, J. N., Jenkins, J. M., Acton, J. S., Bakos, G., Barclay, T., Barkaoui, K., Bhatti, W., Briceño, C., Bryant, E. M., Burleigh, M. R., Ciardi, D. R., Collins, K. A., Collins, K. I., Cooke, B. F. et al. 2020. "Three short-period Jupiters from TESS. HIP 65Ab, TOI-157b, and TOI-169b." Astronomy and Astrophysics 639:A76. https://doi.org/10.1051/0004-6361/202037941
ID: 157772
Type: article
Authors: Nielsen, L. D.; Brahm, R.; Bouchy, F.; Espinoza, N.; Turner, O.; Rappaport, S.; Pearce, L.; Ricker, G.; Vanderspek, R.; Latham, David W.; Seager, S.; Winn, J. N.; Jenkins, J. M.; Acton, J. S.; Bakos, G.; Barclay, T.; Barkaoui, K.; Bhatti, W.; Briceño, C.; Bryant, E. M.; Burleigh, M. R.; Ciardi, D. R.; Collins, K. A.; Collins, K. I.; Cooke, B. F.; Csubry, Z.; dos Santos, L. A.; Eigmüller, Ph; Fausnaugh, M. M.; Gan, T.; Gillon, M.; Goad, M. R.; Guerrero, N.; Hagelberg, J.; Hart, R.; Henning, T.; Huang, C. X.; Jehin, E.; Jenkins, J. S.; Jordán, A.; Kielkopf, J. F.; Kossakowski, D.; Lavie, B.; Law, N.; Lendl, M.; de Leon, J. P.; Lovis, C.; Mann, A. W.; Marmier, M.; McCormac, J.; Mori, M.; Moyano, M.; Narita, N.; Osip, D.; Otegi, J. F.; Pepe, F.; Pozuelos, F. J.; Raynard, L.; Relles, Howard M.; Sarkis, P.; Ségransan, D.; Seidel, J. V.; Shporer, A.; Stalport, M.; Stockdale, C.; Suc, V.; Tamura, M.; Tan, T. G.; Tilbrook, R. H.; Ting, E. B.; Trifonov, T.; Udry, S.; Vanderburg, A.; Wheatley, P. J.; Wingham, G.; Zhan, Z.; Ziegler, C.
Abstract: We report the confirmation and mass determination of three hot Jupiters discovered by the Transiting Exoplanet Survey Satellite (TESS) mission: HIP 65Ab (TOI-129, TIC-201248411) is an ultra-short-period Jupiter orbiting a bright (V = 11.1 mag) K4-dwarf every 0.98 days. It is a massive 3.213 ± 0.078 MJ planet in a grazing transit configuration with an impact parameter of b = 1.17-0.08+0.10. As a result the radius is poorly constrained, 2.03-0.49+0.61RJ. The planet's distance to its host star is less than twice the separation at which it would be destroyed by Roche lobe overflow. It is expected to spiral into HIP 65A on a timescale ranging from 80 Myr to a few gigayears, assuming a reduced tidal dissipation quality factor of Qs' = 107 - 109. We performed a full phase-curve analysis of the TESS data and detected both illumination- and ellipsoidal variations as well as Doppler boosting. HIP 65A is part of a binary stellar system, with HIP 65B separated by 269 AU (3.95 arcsec on sky). TOI-157b (TIC 140691463) is a typical hot Jupiter with a mass of 1.18 ± 0.13 MJ and a radius of 1.29 ± 0.02 RJ. It has a period of 2.08 days, which corresponds to a separation of just 0.03 AU. This makes TOI-157 an interesting system, as the host star is an evolved G9 sub-giant star (V = 12.7). TOI-169b (TIC 183120439) is a bloated Jupiter orbiting a V = 12.4 G-type star. It has a mass of 0.79 ±0.06 MJ and a radius of 1.09-0.05+0.08RJ. Despite having the longest orbital period (P = 2.26 days) of the three planets, TOI-169b receives the most irradiation and is situated on the edge of the Neptune desert. All three host stars are metal rich with [Fe / H] ranging from 0.18 to0.24.
Precise mass and radius of a transiting super-Earth planet orbiting the M dwarf TOI-1235: a planet in the radius gap?Bluhm, P.Luque, R.Espinoza, N.Pallé, E.Caballero, J. A.Dreizler, S.Livingston, J. H.Mathur, S.Quirrenbach, A.Stock, S.Van Eylen, V.Nowak, G.López, E. D.Csizmadia, SzZapatero Osorio, M. R.Schöfer, P.Lillo-Box, J.Oshagh, M.González-Álvarez, E.Amado, P. J.Barrado, D.Béjar, V. J. S.Cale, B.Chaturvedi, P.Cifuentes, C.Cochran, W. D.Collins, Karen A.Collins, K. I.Cortés-Contreras, M.Díez Alonso, E.El Mufti, M.Ercolino, A.Fridlund, M.Gaidos, E.García, R. A.Georgieva, I.González-Cuesta, L.Guerra, P.Hatzes, A. P.Henning, ThHerrero, E.Hidalgo, D.Isopi, G.Jeffers, S. V.Jenkins, J. M.Jensen, E. L. N.Kábath, P.Kaminski, A.Kemmer, J.Korth, J.Kossakowski, D.Kürster, M.Lafarga, M.Mallia, F.Montes, D.Morales, J. C.Morales-Calderón, M.Murgas, F.Narita, N.Passegger, V. M.Pedraz, S.Persson, C. M.Plavchan, P.Rauer, H.Redfield, S.Reffert, S.Reiners, A.Ribas, I.Ricker, G. R.Rodríguez-López, C.Santos, A. R. G.Seager, S.Schlecker, M.Schweitzer, A.Shan, Y.Soto, M. G.Subjak, J.Tal-Or, L.Trifonov, T.Vanaverbeke, S.Vanderspek, R.Wittrock, J.Zechmeister, M.Zohrabi, F.DOI: info:10.1051/0004-6361/202038160v. 639A132
Bluhm, P., Luque, R., Espinoza, N., Pallé, E., Caballero, J. A., Dreizler, S., Livingston, J. H., Mathur, S., Quirrenbach, A., Stock, S., Van Eylen, V., Nowak, G., López, E. D., Csizmadia, Sz, Zapatero Osorio, M. R., Schöfer, P., Lillo-Box, J., Oshagh, M., González-Álvarez, E., Amado, P. J., Barrado, D., Béjar, V. J. S., Cale, B., Chaturvedi, P., Cifuentes, C. et al. 2020. "Precise mass and radius of a transiting super-Earth planet orbiting the M dwarf TOI-1235: a planet in the radius gap?." Astronomy and Astrophysics 639:A132. https://doi.org/10.1051/0004-6361/202038160
ID: 157773
Type: article
Authors: Bluhm, P.; Luque, R.; Espinoza, N.; Pallé, E.; Caballero, J. A.; Dreizler, S.; Livingston, J. H.; Mathur, S.; Quirrenbach, A.; Stock, S.; Van Eylen, V.; Nowak, G.; López, E. D.; Csizmadia, Sz; Zapatero Osorio, M. R.; Schöfer, P.; Lillo-Box, J.; Oshagh, M.; González-Álvarez, E.; Amado, P. J.; Barrado, D.; Béjar, V. J. S.; Cale, B.; Chaturvedi, P.; Cifuentes, C.; Cochran, W. D.; Collins, Karen A.; Collins, K. I.; Cortés-Contreras, M.; Díez Alonso, E.; El Mufti, M.; Ercolino, A.; Fridlund, M.; Gaidos, E.; García, R. A.; Georgieva, I.; González-Cuesta, L.; Guerra, P.; Hatzes, A. P.; Henning, Th; Herrero, E.; Hidalgo, D.; Isopi, G.; Jeffers, S. V.; Jenkins, J. M.; Jensen, E. L. N.; Kábath, P.; Kaminski, A.; Kemmer, J.; Korth, J.; Kossakowski, D.; Kürster, M.; Lafarga, M.; Mallia, F.; Montes, D.; Morales, J. C.; Morales-Calderón, M.; Murgas, F.; Narita, N.; Passegger, V. M.; Pedraz, S.; Persson, C. M.; Plavchan, P.; Rauer, H.; Redfield, S.; Reffert, S.; Reiners, A.; Ribas, I.; Ricker, G. R.; Rodríguez-López, C.; Santos, A. R. G.; Seager, S.; Schlecker, M.; Schweitzer, A.; Shan, Y.; Soto, M. G.; Subjak, J.; Tal-Or, L.; Trifonov, T.; Vanaverbeke, S.; Vanderspek, R.; Wittrock, J.; Zechmeister, M.; Zohrabi, F.
Abstract: We report the confirmation of a transiting planet around the bright weakly active M0.5 V star TOI-1235 (TYC 4384-1735-1, V ≈ 11.5 mag), whose transit signal was detected in the photometric time series of sectors 14, 20, and 21 of the TESS space mission. We confirm the planetary nature of the transit signal, which has a period of 3.44 d, by using precise RV measurements with the CARMENES, HARPS-N, and iSHELL spectrographs, supplemented by high-resolution imaging and ground-based photometry. A comparison of the properties derived for TOI-1235 b with theoretical models reveals that the planet has a rocky composition, with a bulk density slightly higher than that of Earth. In particular, we measure a mass of Mp = 5.9 ± 0.6 M and a radius of Rp = 1.69 ± 0.08 R, which together result in a density of ρp = 6.7- 1.1+ 1.3 g cm-3. When compared with other well-characterized exoplanetary systems, the particular combination of planetary radius and mass places our discovery in the radius gap, which is a transition region between rocky planets and planets with significant atmospheric envelopes. A few examples of planets occupying the radius gap are known to date. While the exact location of the radius gap for M dwarfs is still a matter of debate, our results constrain it to be located at around 1.7 R or larger at the insolation levels received by TOI-1235 b (~60 S). This makes it an extremely interesting object for further studies of planet formation and atmospheric evolution.
Collision of merger and accretion shocks: formation of Mpc-scale contact discontinuity in the Perseus clusterZhang, CongyaoChurazov, EugeneDolag, KlausForman, William R.Zhuravleva, IrinaDOI: info:10.1093/mnrasl/slaa147v. 498L130–L134
Zhang, Congyao, Churazov, Eugene, Dolag, Klaus, Forman, William R., and Zhuravleva, Irina. 2020. "Collision of merger and accretion shocks: formation of Mpc-scale contact discontinuity in the Perseus cluster." Monthly Notices of the Royal Astronomical Society 498:L130– L134. https://doi.org/10.1093/mnrasl/slaa147
ID: 157774
Type: article
Authors: Zhang, Congyao; Churazov, Eugene; Dolag, Klaus; Forman, William R.; Zhuravleva, Irina
Abstract: Two Mpc-size contact discontinuities have recently been identified in the XMM-Newton and Suzaku X-ray observations in the outskirts of the Perseus cluster (Walker et al.). These structures have been tentatively interpreted as 'sloshing cold fronts', which are customarily associated with differential motions of the cluster gas, perturbed by a merger. In this study, we consider an alternative scenario, namely, that the most prominent discontinuity, near the cluster virial radius, is the result of the collision between the accretion shock and a 'runaway' merger shock. We also discuss the possible origin of the second discontinuity at ${\sim}1.2{\rm \, Mpc}$ .
Encounters of merger and accretion shocks in galaxy clusters and their effects on intracluster mediumZhang, CongyaoChurazov, EugeneDolag, KlausForman, William R.Zhuravleva, IrinaDOI: info:10.1093/mnras/staa1013v. 4944539–4547
Zhang, Congyao, Churazov, Eugene, Dolag, Klaus, Forman, William R., and Zhuravleva, Irina. 2020. "Encounters of merger and accretion shocks in galaxy clusters and their effects on intracluster medium." Monthly Notices of the Royal Astronomical Society 494:4539– 4547. https://doi.org/10.1093/mnras/staa1013
ID: 157775
Type: article
Authors: Zhang, Congyao; Churazov, Eugene; Dolag, Klaus; Forman, William R.; Zhuravleva, Irina
Abstract: Several types/classes of shocks naturally arise during formation and evolution of galaxy clusters. One such class is represented by accretion shocks, associated with deceleration of infalling baryons. Such shocks, characterized by a very high Mach number, are present even in 1D models of cluster evolution. Another class is composed of 'runaway merger shocks', which appear when a merger shock, driven by a sufficiently massive infalling subcluster, propagates away from the main-cluster centre. We argue that, when the merger shock overtakes the accretion shock, a new long-living shock is formed that propagates to large distances from the main cluster (well beyond its virial radius), affecting the cold gas around the cluster. We refer to these structures as Merger-accelerated Accretion shocks (MA-shocks) in this paper. We show examples of such MA-shocks in one-dimensioanal (1D) and three-dimensional (3D) simulations and discuss their characteristic properties. In particular, (1) MA-shocks shape the boundary separating the hot intracluster medium (ICM) from the unshocked gas, giving this boundary a 'flower-like' morphology. In 3D, MA-shocks occupy space between the dense accreting filaments. (2) Evolution of MA-shocks highly depends on the Mach number of the runaway merger shock and the mass accretion rate parameter of the cluster. (3) MA-shocks may lead to the misalignment of the ICM boundary and the splashback radius.
On the AGN Nature of Two UV-bright Sources at zspec ∼ 5.5 in the CANDELS Fields: An Update on the AGN Space Density at M1450 ∼ -22.5Grazian, A.Giallongo, E.Fiore, F.Boutsia, K.Civano, FrancescaCristiani, S.Cupani, G.Dickinson, M.Fontanot, F.Menci, N.Romano, M.DOI: info:10.3847/1538-4357/ab99a3v. 89794
Grazian, A., Giallongo, E., Fiore, F., Boutsia, K., Civano, Francesca, Cristiani, S., Cupani, G., Dickinson, M., Fontanot, F., Menci, N., and Romano, M. 2020. "On the AGN Nature of Two UV-bright Sources at zspec ∼ 5.5 in the CANDELS Fields: An Update on the AGN Space Density at M1450 ∼ -22.5." The Astrophysical Journal 897:94. https://doi.org/10.3847/1538-4357/ab99a3
ID: 157776
Type: article
Authors: Grazian, A.; Giallongo, E.; Fiore, F.; Boutsia, K.; Civano, Francesca; Cristiani, S.; Cupani, G.; Dickinson, M.; Fontanot, F.; Menci, N.; Romano, M.
Abstract: It is widespread opinion that hydrogen reionization is mainly driven by primeval star-forming galaxies, with high-z active galactic nuclei (AGNs) having a minor role. Recent observations, however, challenge this notion, indicating a number of issues related to a galaxy-driven reionization scenario. We provide here an updated assessment of the space density of relatively faint (M1450 ∼ -22.5) AGNs at zspec ∼ 5.5 in order to improve the estimate of the photoionization rate contribution from accreting supermassive black holes. Exploiting deep UV rest-frame ground-based spectra collected at the Very Large Telescope on the CANDELS/GOODS-South field and deep Chandra X-ray images in the CANDELS/GOODS-North and EGS areas, we find two relatively bright (M1450 ∼ -22.5) AGNs at zspec ∼ 5.5. We derive an AGN space density of Φ = 1.29 × 10-6 cMpc-3 at z ∼ 5.5 and M1450 ∼ -22.5 by simply dividing their observed number by the cosmological volume in the range 5.0 ∼ -22.5 by simply dividing their observed number by the cosmological volume in the range 5.0 5, in contrast with previous claims mostly based on standard color selection, possibly affected by significant incompleteness. Our estimate for the AGN photoionization rate at z ∼ 5.5 is in agreement with the observed values at similar redshifts, which are needed to keep the intergalactic medium highly ionized. Upcoming James Webb Space Telescope and giant ground-based telescopes observations will improve the study of high-z AGNs and their contribution to the reionization of the universe.
The MOSDEF survey: an improved Voronoi binning technique on spatially resolved stellar populations at z ∼ 2Fetherolf, TaraReddy, Naveen A.Shapley, Alice E.Kriek, MariskaSiana, BrianCoil, Alison L.Mobasher, BahramFreeman, William R.Sanders, Ryan L.Price, Sedona H.Shivaei, IreneAzadi, Mojegande Groot, LauraLeung, Gene C. K.Zick, Tom O.DOI: info:10.1093/mnras/staa2775v. 4985009–5029
Fetherolf, Tara, Reddy, Naveen A., Shapley, Alice E., Kriek, Mariska, Siana, Brian, Coil, Alison L., Mobasher, Bahram, Freeman, William R., Sanders, Ryan L., Price, Sedona H., Shivaei, Irene, Azadi, Mojegan, de Groot, Laura, Leung, Gene C. K., and Zick, Tom O. 2020. "The MOSDEF survey: an improved Voronoi binning technique on spatially resolved stellar populations at z ∼ 2." Monthly Notices of the Royal Astronomical Society 498:5009– 5029. https://doi.org/10.1093/mnras/staa2775
ID: 157643
Type: article
Authors: Fetherolf, Tara; Reddy, Naveen A.; Shapley, Alice E.; Kriek, Mariska; Siana, Brian; Coil, Alison L.; Mobasher, Bahram; Freeman, William R.; Sanders, Ryan L.; Price, Sedona H.; Shivaei, Irene; Azadi, Mojegan; de Groot, Laura; Leung, Gene C. K.; Zick, Tom O.
Abstract: We use a sample of 350 star-forming galaxies at 1.25 160-band alone, we introduce a modified Voronoi binning method that additionally incorporates the S/N distribution of several resolved filters. The spectral energy distribution (SED)-derived resolved E(B - V)stars, stellar population ages, star-formation rates (SFRs), and stellar masses that are inferred from the Voronoi bins constructed from multiple filters are generally consistent with the properties inferred from the integrated photometry within the uncertainties, with the exception of the inferred E(B - V)stars from our z ∼ 1.5 sample due to their UV slopes being unconstrained by the resolved photometry. The results from our multifilter Voronoi binning technique are compared to those derived from a 'traditional' single-filter Voronoi binning approach. We find that single-filter binning produces inferred E(B - V)stars that are systematically redder by 0.02 mag, on average, but could differ by up to 0.20 mag and could be attributed to poorly constrained resolved photometry covering the UV slope. Overall, we advocate that our methodology produces more reliable SED-derived parameters due to the best-fitting resolved SEDs being better constrained at all resolved wavelengths - particularly those covering the UV slope.
The MOSDEF Survey: The Variation of the Dust Attenuation Curve with MetallicityShivaei, IreneReddy, NaveenRieke, GeorgeShapley, AliceKriek, MariskaBattisti, AndrewMobasher, BahramSanders, RyanFetherolf, TaraAzadi, MojeganCoil, Alison L.Freeman, William R.de Groot, LauraLeung, GenePrice, Sedona H.Siana, BrianZick, TomDOI: info:10.3847/1538-4357/aba35ev. 899117
Shivaei, Irene, Reddy, Naveen, Rieke, George, Shapley, Alice, Kriek, Mariska, Battisti, Andrew, Mobasher, Bahram, Sanders, Ryan, Fetherolf, Tara, Azadi, Mojegan, Coil, Alison L., Freeman, William R., de Groot, Laura, Leung, Gene, Price, Sedona H., Siana, Brian, and Zick, Tom. 2020. "The MOSDEF Survey: The Variation of the Dust Attenuation Curve with Metallicity." The Astrophysical Journal 899:117. https://doi.org/10.3847/1538-4357/aba35e
ID: 157644
Type: article
Authors: Shivaei, Irene; Reddy, Naveen; Rieke, George; Shapley, Alice; Kriek, Mariska; Battisti, Andrew; Mobasher, Bahram; Sanders, Ryan; Fetherolf, Tara; Azadi, Mojegan; Coil, Alison L.; Freeman, William R.; de Groot, Laura; Leung, Gene; Price, Sedona H.; Siana, Brian; Zick, Tom
Abstract: We derive a UV-optical stellar dust attenuation curve of galaxies at z = 1.4-2.6 as a function of gas-phase metallicity. We use a sample of 218 star-forming galaxies, excluding those with very young or heavily obscured star formation, from the MOSFIRE Deep Evolution Field survey with Hα, Hβ, and [N II]λ 6585 spectroscopic measurements. We constrain the shape of the attenuation curve by comparing the average flux densities of galaxies sorted into bins of dust obscuration using Balmer decrements, i.e., Hα-to-Hβ luminosities. The average attenuation curve for the high-metallicity sample ( $12+\mathrm{log}({\rm{O}}/{\rm{H}})\gt 8.5$ , corresponding to ${M}_{* }\gtrsim {10}^{10.4}$ ${M}_{\odot }$ ) has a shallow slope, identical to that of the Calzetti local starburst curve, and a significant UV 2175 Å extinction bump that is ∼0.5× the strength of the Milky Way bump. On the other hand, the average attenuation curve of the low-metallicity sample ( $12+\mathrm{log}({\rm{O}}/{\rm{H}})\sim 8.2-8.5$ ) has a steeper slope similar to that of the SMC curve, only consistent with the Calzetti slope at the 3σ level. The UV bump is not detected in the low-metallicity curve, indicating the relative lack of the small dust grains causing the bump at low metallicities. Furthermore, we find that on average the nebular reddening (E(B - V)) is a factor of 2 times larger than that of the stellar continuum for galaxies with low metallicities, while the nebular and stellar reddening are similar for galaxies with higher metallicities. The latter is likely due to a high surface density of dusty clouds embedding the star-forming regions but also reddening the continuum in the high-metallicity galaxies.
RGS Observations of Ejecta Knots in Tycho's Supernova RemnantWilliams, Brian J.Katsuda, SatoruCumbee, RenataPetre, RobertRaymond, John C.Uchida, HiroyukiDOI: info:10.3847/2041-8213/aba7c1v. 898L51
Williams, Brian J., Katsuda, Satoru, Cumbee, Renata, Petre, Robert, Raymond, John C., and Uchida, Hiroyuki. 2020. "RGS Observations of Ejecta Knots in Tycho's Supernova Remnant." The Astrophysical Journal 898:L51. https://doi.org/10.3847/2041-8213/aba7c1
ID: 157645
Type: article
Authors: Williams, Brian J.; Katsuda, Satoru; Cumbee, Renata; Petre, Robert; Raymond, John C.; Uchida, Hiroyuki
Abstract: We present results from XMM-Newton/Reflection Grating Spectrometer (RGS) observations of prominent knots in the southernmost portion of Tycho's supernova remnant, known to be the remnant of a Type Ia supernova in 1572 C.E. By dispersing the photons from these knots out of the remnant with very little emission in front of or behind them, we obtained the nearly uncontaminated spectra of the knots. In the southernmost knot, the RGS successfully resolved numerous emission lines from Si, Ne, O Heα and Lyα, and Fe L-shell. This is the first clear detection of O lines in Tycho's supernova remnant. Line broadening was measured to be ∼3 eV for the O Heα and ∼4.5 eV for the Fe L lines. If we attribute the broadening to pure thermal Doppler effects, then we obtain kTO and kTFe to be ∼400 keV and 1.5 MeV, respectively. These temperatures can be explained by heating in a reverse shock with a shock velocity of ∼3500 km s-1. The abundances obtained from fitting the RGS and MOS data together imply substantially elevated amounts of these materials, confirming previous studies that the knots are heated by a reverse shock, and thus contain ejecta material from the supernova. We are unable to find a Type Ia explosion model that reproduces these abundances, but this is likely the result of this knot being too small to extrapolate to the entire remnant.
A Redshifted Inner Disk Atmosphere and Transient Absorbers in the Ultracompact Neutron Star X-Ray Binary 4U 1916-053Trueba, NicolasMiller, J. M.Fabian, A. C.Kaastra, J.Kallman, T.Lohfink, A.Proga, D.Raymond, JohnReynolds, C.Reynolds, M.Zoghbi, A.DOI: info:10.3847/2041-8213/aba9dev. 899L16
Trueba, Nicolas, Miller, J. M., Fabian, A. C., Kaastra, J., Kallman, T., Lohfink, A., Proga, D., Raymond, John, Reynolds, C., Reynolds, M., and Zoghbi, A. 2020. "A Redshifted Inner Disk Atmosphere and Transient Absorbers in the Ultracompact Neutron Star X-Ray Binary 4U 1916-053." The Astrophysical Journal 899:L16. https://doi.org/10.3847/2041-8213/aba9de
ID: 157646
Type: article
Authors: Trueba, Nicolas; Miller, J. M.; Fabian, A. C.; Kaastra, J.; Kallman, T.; Lohfink, A.; Proga, D.; Raymond, John; Reynolds, C.; Reynolds, M.; Zoghbi, A.
Abstract: The very small accretion disks in ultracompact X-ray binaries are special laboratories in which to study disk accretion and outflows. We report on three sets of new (250 ks total) and archival (50 ks) Chandra/HETG observations of the "dipping" neutron star X-ray binary 4U 1916-053, which has an orbital period of P ≃ 50 minutes. We find that the bulk of the absorption in all three spectra originates in a disk atmosphere that is redshifted by v ≃ 220-290 km s-1, corresponding to the gravitational redshift at a radius of R ∼ 1200 GM/c2. This shift is present in the strongest, most highly ionized lines (Si XIV and Fe XXVI), with a significance of 5σ. Absorption lines observed during dipping events (typically associated with the outermost disk) instead display no velocity shifts and serve as a local standard of rest, suggesting that the redshift is intrinsic to an inner disk atmosphere and not due to radial motion in the galaxy or a kick. In two spectra, there is also evidence of a more strongly redshifted component that would correspond to a disk atmosphere at R ∼ 70 GM/c2; this component is significant at the 3σ level. Finally, in one spectrum, we find evidence of a disk wind with a blueshift of $v=-{1700}_{-1200}^{+1700}\,\mathrm{km}\,{{\rm{s}}}^{-1}$ . If real, this wind would require magnetic driving.
The Role of Turbulence for Heating Plasmas in Eruptive Solar FlaresYe, JingCai, QiangweiShen, ChengcaiRaymond, John C.Lin, JunRoussev, Ilia I.Mei, ZhixingDOI: info:10.3847/1538-4357/ab93b5v. 89764
Ye, Jing, Cai, Qiangwei, Shen, Chengcai, Raymond, John C., Lin, Jun, Roussev, Ilia I., and Mei, Zhixing. 2020. "The Role of Turbulence for Heating Plasmas in Eruptive Solar Flares." The Astrophysical Journal 897:64. https://doi.org/10.3847/1538-4357/ab93b5
ID: 157647
Type: article
Authors: Ye, Jing; Cai, Qiangwei; Shen, Chengcai; Raymond, John C.; Lin, Jun; Roussev, Ilia I.; Mei, Zhixing
Abstract: Magnetohydrodynamic turbulence is ubiquitous in the process of solar eruptions, and it is crucial for the fast release of energy and the formation of complex thermal structures that have been found in observations. In this paper, we focus on the turbulence in two specific regions: inside the current sheet (CS) and above the flare loops, considering the standard flare model. The gravitationally stratified solar atmosphere is used in MHD simulations, which include the Lundquist number of S = 106, thermal conduction, and radiative cooling. The numerical results are generally consistent with previous simulation work, especially the thermal structures and reconnection rate in flare phases. We can observe the formation of multiple termination shocks (TSs) as well as plasmoid collisions, which make the region above the loop-top more turbulent and heat plasmas to the higher temperature. The spectrum studies show that the property of the MHD turbulence inside the CS is anisotropic, while it is quasi-isotropic above the loop-top. The magnetic spectrum becomes softer when the plasmoids interact with the multiple TSs. Meanwhile, synthetic images and light curves of the Solar Dynamics Observatory/Atmospheric Imaging Assembly 94, 131, 171, 304, and 193 Å channels show intermittent radiation enhancement by turbulence above the loop-top. The spectrum study of the radiation intensity in these five wavelengths gives quite different power indices at the same time. In particular, quasiperiodic pulsations (QPPs) in the turbulent region above the loop-top are investigated, and we also confirm that the heating for plasmas via turbulence is an important contributor to the source of QPPs.
Erratum: 'A Deep Near-infrared [Fe II]+[Si I] Emission Line Image of the Supernova Remnant Cassiopeia A' (2018, ApJ, 866, 139)Koo, Bon-ChulKim, Hyun-JeongLee, Yong-HyunRaymond, John C.Lee, Jae-JoonYoon, Sung-ChulMoon, Dae-SikDOI: info:10.3847/1538-4357/ab980cv. 896177
Koo, Bon-Chul, Kim, Hyun-Jeong, Lee, Yong-Hyun, Raymond, John C., Lee, Jae-Joon, Yoon, Sung-Chul, and Moon, Dae-Sik. 2020. "Erratum: "A Deep Near-infrared [Fe II]+[Si I] Emission Line Image of the Supernova Remnant Cassiopeia A" (2018, ApJ, 866, 139)." The Astrophysical Journal 896:177. https://doi.org/10.3847/1538-4357/ab980c
ID: 157648
Type: article
Authors: Koo, Bon-Chul; Kim, Hyun-Jeong; Lee, Yong-Hyun; Raymond, John C.; Lee, Jae-Joon; Yoon, Sung-Chul; Moon, Dae-Sik
Roadmap on cosmic EUV and x-ray spectroscopySmith, RandallHahn, MichaelRaymond, JohnKallman, T.Ballance, C. P.Polito, VanessaDel Zanna, GiulioGu, LiyiHell, NatalieCumbee, RenataBetancourt-Martinez, GabrieleCostantini, ElisaCorrales, LiaDOI: info:10.1088/1361-6455/ab69aav. 53092001
Smith, Randall, Hahn, Michael, Raymond, John, Kallman, T., Ballance, C. P., Polito, Vanessa, Del Zanna, Giulio, Gu, Liyi, Hell, Natalie, Cumbee, Renata, Betancourt-Martinez, Gabriele, Costantini, Elisa, and Corrales, Lia. 2020. "Roadmap on cosmic EUV and x-ray spectroscopy." Journal of Physics B Atomic Molecular Physics 53:092001. https://doi.org/10.1088/1361-6455/ab69aa
ID: 157649
Type: article
Authors: Smith, Randall; Hahn, Michael; Raymond, John; Kallman, T.; Ballance, C. P.; Polito, Vanessa; Del Zanna, Giulio; Gu, Liyi; Hell, Natalie; Cumbee, Renata; Betancourt-Martinez, Gabriele; Costantini, Elisa; Corrales, Lia
Abstract: Cosmic EUV/x-ray spectroscopists, including both solar and astrophysical analysts, have a wide range of high-resolution and high-sensitivity tools in use and a number of new facilities in development for launch. As this bandpass requires placing the spectrometer beyond the Earth's atmosphere, each mission represents a major investment by a national space agency such as NASA, ESA, or JAXA, and more typically a collaboration between two or three. In general justifying new mission requires an improvement in capabilities of at least an order of magnitude, but the sensitivity of these existing missions are already taxing existing atomic data quantity and accuracy. This roadmap reviews the existing missions, showing how in a number of areas atomic data limits the science that can be performed. The missions that will be launched in the coming Decade will without doubt require both more and improved measurements of wavelengths and rates, along with theoretical calculations of collisional and radiative cross sections for a wide range of processes.
G107.0+9.0: a new large optically bright, radio, and X-Ray faint galactic supernova remnant in CepheusFesen, Robert A.Weil, Kathryn E.Raymond, John C.Huet, LaurentRusterholz, Martindi Cicco, DennisMittelman, DavidWalker, SeanDrechsler, MarcelFaworski, SheldonDOI: info:10.1093/mnras/staa2765v. 4985194–5206
Fesen, Robert A., Weil, Kathryn E., Raymond, John C., Huet, Laurent, Rusterholz, Martin, di Cicco, Dennis, Mittelman, David, Walker, Sean, Drechsler, Marcel, and Faworski, Sheldon. 2020. "G107.0+9.0: a new large optically bright, radio, and X-Ray faint galactic supernova remnant in Cepheus." Monthly Notices of the Royal Astronomical Society 498:5194– 5206. https://doi.org/10.1093/mnras/staa2765
ID: 157650
Type: article
Authors: Fesen, Robert A.; Weil, Kathryn E.; Raymond, John C.; Huet, Laurent; Rusterholz, Martin; di Cicco, Dennis; Mittelman, David; Walker, Sean; Drechsler, Marcel; Faworski, Sheldon
Abstract: Wide-field H α images of the Galactic plane have revealed a new supernova remnant (SNR) nearly 3 deg in diameter centred at l = 107.0, b = +9.0. Deep and higher resolution H α and [O III] 5007 Å images show dozens of H α filaments along the remnant's northern, western, and southwestern limbs, but few [O III] bright filaments. The nebula is well detected in the H α Virginia Tech Spectral-Line Survey images, with many of its brighter filaments even visible on Digital Sky Survey images. Low-dispersion spectra of several filaments show either Balmer dominated, non-radiative filaments, or the more common SNR radiative filaments with [S II]/H α ratios above 0.5, consistent with shock-heated line emission. Emission line ratios suggest shock velocities ranging from ≤70 km s-1 along its western limb to ≃ 100 km s-1 along its northwestern boundary. While no associated X-ray emission is seen in ROSAT images, faint 1420 MHz radio emission appears coincident with its western and northern limbs. Based on an analysis of the remnant's spatially resolved H α and [O III] emissions, we estimate the remnant's distance at ∼1.5-2.0 kpc implying a physically large (dia. = 75-100 pc) and old (90-110 × 103 yr) SNR in its post-Sedov radiative phase of evolution expanding into a low-density interstellar medium (n0 = 0.05-0.2 cm-3) and lying some 250-300 pc above the Galactic plane.
Craters on Charon: Impactors from a Collisional Cascade Among Trans-Neptunian ObjectsKenyon, Scott J.Bromley, Benjamin C.DOI: info:10.3847/PSJ/aba8a9v. 140
Kenyon, Scott J. and Bromley, Benjamin C. 2020. "Craters on Charon: Impactors from a Collisional Cascade Among Trans-Neptunian Objects." The Planetary Science Journal 1:40. https://doi.org/10.3847/PSJ/aba8a9
ID: 157651
Type: article
Authors: Kenyon, Scott J.; Bromley, Benjamin C.
Abstract: We consider whether equilibrium size distributions from collisional cascades match the frequency of impactors derived from New Horizons crater counts on Charon. Using an analytic model and a suite of numerical simulations, we demonstrate that collisional cascades generate wavy size distributions; the morphology of the waves depends on the binding energy of solids ${Q}_{D}^{\star }$ and the collision velocity vc. For an adopted minimum size of solids, ${r}_{\min }$ = 1 μm, and collision velocity vc = 1-3 km s-1, the waves are rather insensitive to the gravitational component of ${Q}_{D}^{\star }$ . If the bulk strength component of ${Q}_{D}^{\star }$ is ${Q}_{s}{r}^{{e}_{s}}$ for particles with radius r, size distributions with small Qs are much wavier than those with large Qs; systems with es ≍ -0.4 have stronger waves than systems with es ≍ 0. Detailed comparisons with the New Horizons data suggest that a collisional cascade among solids with a bulk strength intermediate between weak ice and normal ice produces size distributions fairly similar to that of impactors on Charon. If the surface density Σ of the protosolar nebula varies with semimajor axis a as Σ ≍ 30 g cm-2 (a/1 au)-3/2, the timescale for a cascade to generate an approximate equilibrium is 100-300 Myr at 45 au and 10-30 Myr at 25 au. Although it is necessary to perform more complete evolutionary calculations of the Kuiper Belt, collisional cascades are a viable model for producing the size distribution of solids that impacted Charon throughout its history.
A Pluto-Charon Concerto: An Impact on Charon as the Origin of the Small SatellitesBromley, Benjamin C.Kenyon, Scott J.DOI: info:10.3847/1538-3881/ab9e6cv. 16085
Bromley, Benjamin C. and Kenyon, Scott J. 2020. "A Pluto-Charon Concerto: An Impact on Charon as the Origin of the Small Satellites." The Astronomical Journal 160:85. https://doi.org/10.3847/1538-3881/ab9e6c
ID: 157652
Type: article
Authors: Bromley, Benjamin C.; Kenyon, Scott J.
Abstract: We consider a scenario where the small satellites of Pluto and Charon grew within a disk of debris from an impact between Charon and a trans-Neptunian object (TNO). After Charon's orbital motion boosts the debris into a disk-like structure, rapid orbital damping of meter-sized or smaller objects is essential to prevent the subsequent reaccretion or dynamical ejection by the binary. From analytical estimates and simulations of disk evolution, we estimate an impactor radius of 30-100 km; smaller (larger) radii apply to an oblique (direct) impact. Although collisions between large TNOs and Charon are unlikely today, they were relatively common within the first 0.1-1 Gyr of the solar system. Compared to models where the small satellites agglomerate in the debris left over by the giant impact that produced the Pluto-Charon binary planet, satellite formation from a later impact on Charon avoids the destabilizing resonances that sweep past the satellites during the early orbital expansion of the binary.
Proton core behaviour inside magnetic field switchbacksWoolley, ThomasMatteini, LorenzoHorbury, Timothy S.Bale, Stuart D.Woodham, Lloyd D.Laker, RonanAlterman, Benjamin L.Bonnell, John W.Case, Anthony W.Kasper, Justin C.Klein, Kristopher G.Martinović, Mihailo M.Stevens, MichaelDOI: info:10.1093/mnras/staa2770v. 4985524–5531
Woolley, Thomas, Matteini, Lorenzo, Horbury, Timothy S., Bale, Stuart D., Woodham, Lloyd D., Laker, Ronan, Alterman, Benjamin L., Bonnell, John W., Case, Anthony W., Kasper, Justin C., Klein, Kristopher G., Martinović, Mihailo M., and Stevens, Michael. 2020. "Proton core behaviour inside magnetic field switchbacks." Monthly Notices of the Royal Astronomical Society 498:5524– 5531. https://doi.org/10.1093/mnras/staa2770
ID: 157653
Type: article
Authors: Woolley, Thomas; Matteini, Lorenzo; Horbury, Timothy S.; Bale, Stuart D.; Woodham, Lloyd D.; Laker, Ronan; Alterman, Benjamin L.; Bonnell, John W.; Case, Anthony W.; Kasper, Justin C.; Klein, Kristopher G.; Martinović, Mihailo M.; Stevens, Michael
Abstract: During Parker Solar Probe's first two orbits, there are widespread observations of rapid magnetic field reversals known as switchbacks. These switchbacks are extensively found in the near-Sun solar wind, appear to occur in patches, and have possible links to various phenomena such as magnetic reconnection near the solar surface. As switchbacks are associated with faster plasma flows, we questioned whether they are hotter than the background plasma and whether the microphysics inside a switchback is different to its surroundings. We have studied the reduced distribution functions from the Solar Probe Cup instrument and considered time periods with markedly large angular deflections to compare parallel temperatures inside and outside switchbacks. We have shown that the reduced distribution functions inside switchbacks are consistent with a rigid velocity space rotation of the background plasma. As such, we conclude that the proton core parallel temperature is very similar inside and outside of switchbacks, implying that a temperature-velocity (T-V) relationship does not hold for the proton core parallel temperature inside magnetic field switchbacks. We further conclude that switchbacks are consistent with Alfvénic pulses travelling along open magnetic field lines. The origin of these pulses, however, remains unknown. We also found that there is no obvious link between radial Poynting flux and kinetic energy enhancements suggesting that the radial Poynting flux is not important for the dynamics of switchbacks.
Energetic Particle Increases Associated with Stream Interaction RegionsCohen, C. M. S.Christian, E. R.Cummings, A. C.Davis, A. J.Desai, M. I.Giacalone, J.Hill, M. E.Joyce, C. J.Labrador, A. W.Leske, R. A.Matthaeus, W. H.McComas, D. J.McNutt, R. L., Jr.Mewaldt, R. A.Mitchell, D. G.Rankin, J. S.Roelof, E. C.Schwadron, N. A.Stone, E. C.Szalay, J. R.Wiedenbeck, M. E.Allen, R. C.Ho, G. C.Jian, L. K.Lario, D.Odstrcil, D.Bale, S. D.Badman, S. T.Pulupa, M.MacDowall, R. J.Kasper, Justin C.Case, Anthony W.Korreck, Kelly E.Larson, D. E.Livi, RobertoStevens, Michael L.Whittlesey, PhyllisDOI: info:10.3847/1538-4365/ab4c38v. 24620
Cohen, C. M. S., Christian, E. R., Cummings, A. C., Davis, A. J., Desai, M. I., Giacalone, J., Hill, M. E., Joyce, C. J., Labrador, A. W., Leske, R. A., Matthaeus, W. H., McComas, D. J., McNutt, R. L., Jr., Mewaldt, R. A., Mitchell, D. G., Rankin, J. S., Roelof, E. C., Schwadron, N. A., Stone, E. C., Szalay, J. R., Wiedenbeck, M. E., Allen, R. C., Ho, G. C., Jian, L. K., Lario, D. et al. 2020. "Energetic Particle Increases Associated with Stream Interaction Regions." The Astrophysical Journal Supplement Series 246:20. https://doi.org/10.3847/1538-4365/ab4c38
ID: 157654
Type: article
Authors: Cohen, C. M. S.; Christian, E. R.; Cummings, A. C.; Davis, A. J.; Desai, M. I.; Giacalone, J.; Hill, M. E.; Joyce, C. J.; Labrador, A. W.; Leske, R. A.; Matthaeus, W. H.; McComas, D. J.; McNutt, R. L., Jr.; Mewaldt, R. A.; Mitchell, D. G.; Rankin, J. S.; Roelof, E. C.; Schwadron, N. A.; Stone, E. C.; Szalay, J. R.; Wiedenbeck, M. E.; Allen, R. C.; Ho, G. C.; Jian, L. K.; Lario, D.; Odstrcil, D.; Bale, S. D.; Badman, S. T.; Pulupa, M.; MacDowall, R. J.; Kasper, Justin C.; Case, Anthony W.; Korreck, Kelly E.; Larson, D. E.; Livi, Roberto; Stevens, Michael L.; Whittlesey, Phyllis
Abstract: The Parker Solar Probe was launched on 2018 August 12 and completed its second orbit on 2019 June 19 with perihelion of 35.7 solar radii. During this time, the Energetic Particle Instrument-Hi (EPI-Hi, one of the two energetic particle instruments comprising the Integrated Science Investigation of the Sun, IS☉IS) measured seven proton intensity increases associated with stream interaction regions (SIRs), two of which appear to be occurring in the same region corotating with the Sun. The events are relatively weak, with observed proton spectra extending to only a few MeV and lasting for a few days. The proton spectra are best characterized by power laws with indices ranging from -4.3 to -6.5, generally softer than events associated with SIRs observed at 1 au and beyond. Helium spectra were also obtained with similar indices, allowing He/H abundance ratios to be calculated for each event. We find values of 0.016-0.031, which are consistent with ratios obtained previously for corotating interaction region events with fast solar wind ≤600 km s-1. Using the observed solar wind data combined with solar wind simulations, we study the solar wind structures associated with these events and identify additional spacecraft near 1 au appropriately positioned to observe the same structures after some corotation. Examination of the energetic particle observations from these spacecraft yields two events that may correspond to the energetic particle increases seen by EPI-Hi earlier.
Decomposing the internal faraday rotation of black hole accretion flowsRicarte, AngeloPrather, Ben S.Wong, George N.Narayan, RameshGammie, CharlesJohnson, Michael D.DOI: info:10.1093/mnras/staa2692v. 4985468–5488
Ricarte, Angelo, Prather, Ben S., Wong, George N., Narayan, Ramesh, Gammie, Charles, and Johnson, Michael D. 2020. "Decomposing the internal faraday rotation of black hole accretion flows." Monthly Notices of the Royal Astronomical Society 498:5468– 5488. https://doi.org/10.1093/mnras/staa2692
ID: 157655
Type: article
Authors: Ricarte, Angelo; Prather, Ben S.; Wong, George N.; Narayan, Ramesh; Gammie, Charles; Johnson, Michael D.
Abstract: Faraday rotation has been seen at millimeter wavelengths in several low-luminosity active galactic nuclei, including Event Horizon Telescope (EHT) targets M87* and Sgr A*. The observed rotation measure (RM) probes the density, magnetic field, and temperature of material integrated along the line of sight. To better understand how accretion disc conditions are reflected in the RM, we perform polarized radiative transfer calculations using a set of general relativistic magnetohydrodynamic (GRMHD) simulations appropriate for M87*. We find that in spatially resolved millimetre wavelength images on event horizon scales, the RM can vary by orders of magnitude and even flip sign. The observational consequences of this spatial structure include significant time-variability, sign-flips, and non-λ2 evolution of the polarization plane. For some models, we find that internal RM can cause significant bandwidth depolarization even across the relatively narrow fractional bandwidths observed by the EHT. We decompose the linearly polarized emission in these models based on their RM and find that emission in front of the mid-plane can exhibit orders of magnitude less Faraday rotation than emission originating from behind the mid-plane or within the photon ring. We confirm that the spatially unresolved (i.e. image integrated) RM is a poor predictor of the accretion rate, with substantial scatter stemming from time variability and inclination effects. Models can be constrained with repeated observations to characterize time variability and the degree of non-λ2 evolution of the polarization plane.
The Mass-Size Relation and the Constancy of GMC Surface Densities in the Milky WayLada, Charles J.Dame, Thomas M.DOI: info:10.3847/1538-4357/ab9bfbv. 8983
Lada, Charles J. and Dame, Thomas M. 2020. "The Mass-Size Relation and the Constancy of GMC Surface Densities in the Milky Way." The Astrophysical Journal 898:3. https://doi.org/10.3847/1538-4357/ab9bfb
ID: 157656
Type: article
Authors: Lada, Charles J.; Dame, Thomas M.
Abstract: We use two existing molecular cloud catalogs derived from the same CO survey and two catalogs derived from local dust extinction surveys to investigate the nature of the giant molecular cloud (GMC) mass-size relation in the Galaxy. We find that the four surveys are well described by MGMC ∼ R2, implying a constant mean surface density, ${{\rm{\Sigma }}}_{\mathrm{GMC}}$ , for the cataloged clouds. However, the scaling coefficients and scatter differ significantly between the CO- and extinction-derived relations. We find that the additional scatter seen in the CO relations is due to a systematic variation in ${{\rm{\Sigma }}}_{\mathrm{GMC}}$ with Galactic radius that is unobservable in the local extinction data. We decompose this radial variation of ${{\rm{\Sigma }}}_{\mathrm{GMC}}$ into two components, a linear negative gradient with Galactic radius and a broad peak coincident with the molecular ring and superposed on the linear gradient. We show that the former may be due to a radial dependence of XCO on metallicity, while the latter likely results from a combination of increased surface densities of individual GMCs and a systematic upward bias in the measurements of ${{\rm{\Sigma }}}_{\mathrm{GMC}}$ due to cloud blending in the molecular ring. We attribute the difference in scaling coefficients between the CO and extinction data to an underestimate of XCO. We recalibrate the CO observations of nearby GMCs using extinction measurements to find that locally XCO = 3.6 ± 0.3 × 1020 cm-2 (K km s-1)-1. We conclude that outside the molecular ring, the GMC population of the Galaxy can be described to relatively good precision by a constant ${{\rm{\Sigma }}}_{\mathrm{GMC}}$ of 35 ${M}_{\odot }$ pc-2.
Dual-wavelength ALMA Observations of Dust Rings in Protoplanetary DisksLong, FengPinilla, PaolaHerczeg, Gregory J.Andrews, Sean M.Harsono, DanielJohnstone, DougRagusa, EnricoPascucci, IlariaWilner, David J.Hendler, NathanJennings, JeffLiu, YaoLodato, GiuseppeMenard, Francoisvan de Plas, GerritDipierro, GiovanniDOI: info:10.3847/1538-4357/ab9a54v. 89836
Long, Feng, Pinilla, Paola, Herczeg, Gregory J., Andrews, Sean M., Harsono, Daniel, Johnstone, Doug, Ragusa, Enrico, Pascucci, Ilaria, Wilner, David J., Hendler, Nathan, Jennings, Jeff, Liu, Yao, Lodato, Giuseppe, Menard, Francois, van de Plas, Gerrit, and Dipierro, Giovanni. 2020. "Dual-wavelength ALMA Observations of Dust Rings in Protoplanetary Disks." The Astrophysical Journal 898:36. https://doi.org/10.3847/1538-4357/ab9a54
ID: 157657
Type: article
Authors: Long, Feng; Pinilla, Paola; Herczeg, Gregory J.; Andrews, Sean M.; Harsono, Daniel; Johnstone, Doug; Ragusa, Enrico; Pascucci, Ilaria; Wilner, David J.; Hendler, Nathan; Jennings, Jeff; Liu, Yao; Lodato, Giuseppe; Menard, Francois; van de Plas, Gerrit; Dipierro, Giovanni
Abstract: We present new Atacama Large Millimeter/submillimeter Array observations for three protoplanetary disks in Taurus at 2.9 mm and comparisons with previous 1.3 mm data both at an angular resolution of ∼0"1 (15 au for the distance of Taurus). In the single-ring disk DS Tau, double-ring disk GO Tau, and multiring disk DL Tau, the same rings are detected at both wavelengths, with radial locations spanning from 50 to 120 au. To quantify the dust emission morphology, the observed visibilities are modeled with a parametric prescription for the radial intensity profile. The disk outer radii, taken as 95% of the total flux encircled in the model intensity profiles, are consistent at both wavelengths for the three disks. Dust evolution models show that dust trapping in local pressure maxima in the outer disk could explain the observed patterns. Dust rings are mostly unresolved. The marginally resolved ring in DS Tau shows a tentatively narrower ring at the longer wavelength, an observational feature expected from efficient dust trapping. The spectral index (αmm) increases outward and exhibits local minima that correspond to the peaks of dust rings, indicative of the changes in grain properties across the disks. The low optical depths (τ ∼ 0.1-0.2 at 2.9 mm and 0.2-0.4 at 1.3 mm) in the dust rings suggest that grains in the rings may have grown to millimeter sizes. The ubiquitous dust rings in protoplanetary disks modify the overall dynamics and evolution of dust grains, likely paving the way toward the new generation of planet formation.
Erratum: 'The Disk Substructures at High Angular Resolution Project (DSHARP). II. Characteristics of Annular Substructures' (2018, ApJL, 869, L42)Huang, JaneAndrews, Sean M.Dullemond, Cornelis P.Isella, AndreaPérez, Laura M.Guzmán, Viviana V.Öberg, Karin I.Zhu, ZhaohuanZhang, ShangjiaBai, Xue-NingBenisty, MyriamBirnstiel, TilmanCarpenter, John M.Hughes, A. MeredithRicci, LucaWeaver, ErikWilner, David J.DOI: info:10.3847/2041-8213/aba83bv. 898L57
Huang, Jane, Andrews, Sean M., Dullemond, Cornelis P., Isella, Andrea, Pérez, Laura M., Guzmán, Viviana V., Öberg, Karin I., Zhu, Zhaohuan, Zhang, Shangjia, Bai, Xue-Ning, Benisty, Myriam, Birnstiel, Tilman, Carpenter, John M., Hughes, A. Meredith, Ricci, Luca, Weaver, Erik, and Wilner, David J. 2020. "Erratum: "The Disk Substructures at High Angular Resolution Project (DSHARP). II. Characteristics of Annular Substructures" (2018, ApJL, 869, L42)." The Astrophysical Journal 898:L57. https://doi.org/10.3847/2041-8213/aba83b
ID: 157658
Type: article
Authors: Huang, Jane; Andrews, Sean M.; Dullemond, Cornelis P.; Isella, Andrea; Pérez, Laura M.; Guzmán, Viviana V.; Öberg, Karin I.; Zhu, Zhaohuan; Zhang, Shangjia; Bai, Xue-Ning; Benisty, Myriam; Birnstiel, Tilman; Carpenter, John M.; Hughes, A. Meredith; Ricci, Luca; Weaver, Erik; Wilner, David J.
Large-scale CO Spiral Arms and Complex Kinematics Associated with the T Tauri Star RU LupHuang, JaneAndrews, Sean M.Öberg, Karin I.Ansdell, MeganBenisty, MyriamCarpenter, John M.Isella, AndreaPérez, Laura M.Ricci, LucaWilliams, Jonathan P.Wilner, David J.Zhu, ZhaohuanDOI: info:10.3847/1538-4357/aba1e1v. 898140
Huang, Jane, Andrews, Sean M., Öberg, Karin I., Ansdell, Megan, Benisty, Myriam, Carpenter, John M., Isella, Andrea, Pérez, Laura M., Ricci, Luca, Williams, Jonathan P., Wilner, David J., and Zhu, Zhaohuan. 2020. "Large-scale CO Spiral Arms and Complex Kinematics Associated with the T Tauri Star RU Lup." The Astrophysical Journal 898:140. https://doi.org/10.3847/1538-4357/aba1e1
ID: 157659
Type: article
Authors: Huang, Jane; Andrews, Sean M.; Öberg, Karin I.; Ansdell, Megan; Benisty, Myriam; Carpenter, John M.; Isella, Andrea; Pérez, Laura M.; Ricci, Luca; Williams, Jonathan P.; Wilner, David J.; Zhu, Zhaohuan
Abstract: While protoplanetary disks often appear to be compact and well organized in millimeter continuum emission, CO spectral line observations are increasingly revealing complex behavior at large distances from the host star. We present deep Atacama Large Millimeter/submillimeter Array maps of the J = 2-1 transition of 12CO, 13CO, and C18O, as well as the J = 3-2 transition of DCO+, toward the T Tauri star RU Lup at a resolution of ∼0.3″ (∼50 au). The CO isotopologue emission traces four major components of the RU Lup system: a compact Keplerian disk with a radius of ∼120 au, a non-Keplerian "envelope-like" structure surrounding the disk and extending to ∼260 au from the star, at least five blueshifted spiral arms stretching up to 1000 au, and clumps outside the spiral arms located up to 1500 au in projection from RU Lup. We comment on potential explanations for RU Lup's peculiar gas morphology, including gravitational instability, accretion of material onto the disk, or perturbation by another star. RU Lup's extended non-Keplerian CO emission, elevated stellar accretion rate, and unusual photometric variability suggest that it could be a scaled-down Class II analog of the outbursting FU Ori systems.
An Evolutionary Study of Volatile Chemistry in Protoplanetary DisksBergner, Jennifer B.Öberg, Karin I.Bergin, Edwin A.Andrews, Sean M.Blake, Geoffrey A.Carpenter, John M.Cleeves, L. IlsedoreGuzmán, Viviana V.Huang, JaneJørgensen, Jes K.Qi, ChunhuaSchwarz, Kamber R.Williams, Jonathan P.Wilner, David J.DOI: info:10.3847/1538-4357/ab9e71v. 89897
Bergner, Jennifer B., Öberg, Karin I., Bergin, Edwin A., Andrews, Sean M., Blake, Geoffrey A., Carpenter, John M., Cleeves, L. Ilsedore, Guzmán, Viviana V., Huang, Jane, Jørgensen, Jes K., Qi, Chunhua, Schwarz, Kamber R., Williams, Jonathan P., and Wilner, David J. 2020. "An Evolutionary Study of Volatile Chemistry in Protoplanetary Disks." The Astrophysical Journal 898:97. https://doi.org/10.3847/1538-4357/ab9e71
ID: 157660
Type: article
Authors: Bergner, Jennifer B.; Öberg, Karin I.; Bergin, Edwin A.; Andrews, Sean M.; Blake, Geoffrey A.; Carpenter, John M.; Cleeves, L. Ilsedore; Guzmán, Viviana V.; Huang, Jane; Jørgensen, Jes K.; Qi, Chunhua; Schwarz, Kamber R.; Williams, Jonathan P.; Wilner, David J.
Abstract: The volatile composition of a planet is determined by the inventory of gas and ice in the parent disk. The volatile chemistry in the disk is expected to evolve over time, though this evolution is poorly constrained observationally. We present Atacama Large Millimeter/submillimeter Array observations of C18O, C2H, and the isotopologues H13CN, HC15N, and DCN toward five Class 0/I disk candidates. Combined with a sample of 14 Class II disks presented in Bergner et al., this data set offers a view of volatile chemical evolution over the disk lifetime. Our estimates of C18O abundances are consistent with a rapid depletion of CO in the first ∼0.5-1 Myr of the disk lifetime. We do not see evidence that C2H and HCN formation are enhanced by CO depletion, possibly because the gas is already quite under-abundant in CO. Further CO depletion may actually hinder their production by limiting the gas-phase carbon supply. The embedded sources show several chemical differences compared to the Class II stage, which seem to arise from shielding of radiation by the envelope (impacting C2H formation and HC15N fractionation) and sublimation of ices from infalling material (impacting HCN and C18O abundances). Such chemical differences between Class 0/I and Class II sources may affect the volatile composition of planet-forming material at different stages in the disk lifetime.
Protoplanetary disk masses in NGC 2024: Evidence for two populationsvan Terwisga, S. E.van Dishoeck, E. F.Mann, R. K.Di Francesco, J.van der Marel, N.Meyer, M.Andrews, Sean M.Carpenter, J.Eisner, J. A.Manara, C. F.Williams, J. P.DOI: info:10.1051/0004-6361/201937403v. 640A27
van Terwisga, S. E., van Dishoeck, E. F., Mann, R. K., Di Francesco, J., van der Marel, N., Meyer, M., Andrews, Sean M., Carpenter, J., Eisner, J. A., Manara, C. F., and Williams, J. P. 2020. "Protoplanetary disk masses in NGC 2024: Evidence for two populations." Astronomy and Astrophysics 640:A27. https://doi.org/10.1051/0004-6361/201937403
ID: 157661
Type: article
Authors: van Terwisga, S. E.; van Dishoeck, E. F.; Mann, R. K.; Di Francesco, J.; van der Marel, N.; Meyer, M.; Andrews, Sean M.; Carpenter, J.; Eisner, J. A.; Manara, C. F.; Williams, J. P.
Abstract: Context. Protoplanetary disks in dense, massive star-forming regions are strongly affected by their environment. How this environmental impact changes over time is an important constraint on disk evolution and external photoevaporation models.
Aims: We characterize the dust emission from 179 disks in the core of the young (0.5 Myr) NGC 2024 cluster. By studying how the disk mass varies within the cluster, and comparing these disks to those in other regions, we aim to determine how external photoevaporation influences disk properties over time.
Methods: Using the Atacama Large Millimeter/submillimeter Array, a 2.9'× 2.9' mosaic centered on NGC 2024 FIR 3 was observed at 225 GHz with a resolution of 0.25″, or ~100 AU. The imaged region contains 179 disks identified at IR wavelengths, seven new disk candidates, and several protostars.
Results: The overall detection rate of disks is 32 ± 4%. Few of the disks are resolved, with the exception of a giant (R = 300 AU) transition disk. Serendipitously, we observe a millimeter flare from an X-ray bright young stellar object (YSO), and resolve continuum emission from a Class 0 YSO in the FIR 3 core. Two distinct disk populations are present: a more massive one in the east, along the dense molecular ridge hosting the FIR 1-5 YSOs, with a detection rate of 45 ± 7%. In the western population, towards IRS 1, only 15 ± 4% of disks are detected.
Conclusions: NGC 2024 hosts two distinct disk populations. Disks along the dense molecular ridge are young (0.2-0.5 Myr) and partly shielded from the far ultraviolet radiation of IRS 2b; their masses are similar to isolated 1-3 Myr old SFRs. The western population is older and at lower extinctions, and may be affected by external photoevaporation from both IRS 1 and IRS 2b. However, it is possible these disks had lower masses to begin with.
Tables 1, 2, and B.1 and FITS figure 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/640/A27
Is the primary CoRoT target HD 43587 under a Maunder minimum phase?Ferreira, R. R.Barbosa, R.Castro, M.Guerrero, G.de Almeida, L.Boumier, P.do Nascimento, José-DiasDOI: info:10.1051/0004-6361/201937219v. 640A46
Ferreira, R. R., Barbosa, R., Castro, M., Guerrero, G., de Almeida, L., Boumier, P., and do Nascimento, José-Dias. 2020. "Is the primary CoRoT target HD 43587 under a Maunder minimum phase?." Astronomy and Astrophysics 640:A46. https://doi.org/10.1051/0004-6361/201937219
ID: 157662
Type: article
Authors: Ferreira, R. R.; Barbosa, R.; Castro, M.; Guerrero, G.; de Almeida, L.; Boumier, P.; do Nascimento, José-Dias
Abstract: Context. One of the most enigmatic phenomena related to solar activity is the so-called Maunder minimum phase. It consists in the lowest sunspot count ever registered for the Sun and has not been confirmed for other stars to date. Since the spectroscopic observations of stellar activity at the Mount Wilson Observatory, the solar analog HD 43587 has shown a very low and apparently invariant activity level, which makes it a Maunder minimum candidate.
Aims: We aim to analyze the chromospheric activity evolution of HD 43587 and its evolutive status, with the intention of unraveling the reasons for this low and flat activity.
Methods: We used an activity measurements dataset available in the literature, and computed the S-index from HARPS and NARVAL spectra to infer a cycle period. Additionally, we analyzed the CoRoT light curve of HD 43587, and applied gyrochronology and activity calibrations to determine its rotation period. Finally, based on an evolutionary model and the inferred rotation period, we used the EULAG-MHD code to perform global MHD simulations of HD 43587 to get some insight into its dynamo process.
Results: We confirm the almost flat activity profile, with a cycle period Pcyc = 10.44 ± 3.03 yr deduced from the S-index time series, and a long-term trend that might be a period of more than 50 yr. It was impossible to define a rotation period from the light curve, however gyrochronology and activity calibrations allow us to infer an indirect estimate of ̄Prot = 22.6 ± 1.9 d. Furthermore, the MHD simulations confirm an oscillatory dynamo with a cycle period in good agreement with the observations and a low level of surface magnetic activity.
Conclusions: We conclude that this object might be experiencing a "natural" decrease in magnetic activity as a consequence of its age. Nevertheless, the possibility that HD 43587 is in a Maunder minimum phase cannot be ruled out.
Li abundances for solar twins in the open cluster M67Carlos, MaríliaMeléndez, Jorgedo Nascimento, José-DiasCastro, MatthieuDOI: info:10.1093/mnras/stz3504v. 492245–249
Carlos, Marília, Meléndez, Jorge, do Nascimento, José-Dias, and Castro, Matthieu. 2020. "Li abundances for solar twins in the open cluster M67." Monthly Notices of the Royal Astronomical Society 492:245– 249. https://doi.org/10.1093/mnras/stz3504
ID: 157663
Type: article
Authors: Carlos, Marília; Meléndez, Jorge; do Nascimento, José-Dias; Castro, Matthieu
Abstract: We determine lithium (Li) abundances for solar twins in the M67 open cluster to add valuable information about the correlation between Li depletion and stellar age and, then, better understand stellar structure and evolution. We use high resolution and good signal-to-noise ratio spectra to characterize Li depletion in three solar twins from M67, using spectral synthesis in the region of the asymmetric 6707.75 Å Li I feature. The mean Li abundance value of A(Li) = 1.6 ± 0.2 dex for our sample of M67 solar twins (our three stars plus a fourth solar twin from a previous analysis in the literature) presents Li abundance expected for its age. Also, the scatter estimated from the standard deviation of the Li abundances in this work is similar to the typical scatter found in a sample of field solar twins presented in the literature.
Rotation of Solar Analogs Crossmatching Kepler and Gaia DR2do Nascimento, J. -D, Jr.de Almeida, L.Velloso, E. N.Anthony, F.Barnes, S. A.Saar, Steven H.Meibom, Sørenda Costa, J. S.Castro, M.Galarza, J. Y.Lorenzo-Oliveira, D.Beck, P. G.Meléndez, J.DOI: info:10.3847/1538-4357/ab9c16v. 898173
do Nascimento, J. -D, Jr., de Almeida, L., Velloso, E. N., Anthony, F., Barnes, S. A., Saar, Steven H., Meibom, Søren, da Costa, J. S., Castro, M., Galarza, J. Y., Lorenzo-Oliveira, D., Beck, P. G., and Meléndez, J. 2020. "Rotation of Solar Analogs Crossmatching Kepler and Gaia DR2." The Astrophysical Journal 898:173. https://doi.org/10.3847/1538-4357/ab9c16
ID: 157664
Type: article
Authors: do Nascimento, J. -D, Jr.; de Almeida, L.; Velloso, E. N.; Anthony, F.; Barnes, S. A.; Saar, Steven H.; Meibom, Søren; da Costa, J. S.; Castro, M.; Galarza, J. Y.; Lorenzo-Oliveira, D.; Beck, P. G.; Meléndez, J.
Abstract: A major obstacle to interpreting the rotation period distribution for main-sequence stars from Kepler mission data has been the lack of a precise evolutionary status for these objects. We address this by investigating the evolutionary status based on Gaia Data Release 2 parallaxes and photometry for more than 30,000 Kepler stars with rotation period measurements. Many of these are subgiants and should be excluded in future work on dwarfs. We particularly investigate a 193-star sample of solar analogs and report newly determined rotation periods for 125 of these. These include 54 stars from a prior sample, of which we can confirm the periods for 50. The remainder are new, and 10 of them longer than a solar rotation period, suggesting that Sun-like stars continue to spin down on the main sequence past solar age. Our sample of solar analogs could potentially serve as a benchmark for future missions, such as PLAnetary Transits and Oscillations of stars, and emphasizes the need for additional astrometric, photometric, and spectroscopic information before interpreting the stellar populations and results from time series surveys.
Spatially Resolved Ultraviolet Spectroscopy of the Great Dimming of BetelgeuseDupree, Andrea K.Strassmeier, Klaus G.Matthews, Lynn D.Uitenbroek, HanCalderwood, ThomasGranzer, ThomasGuinan, Edward F.Leike, ReimarMontargès, MiguelRichards, Anita M. S.Wasatonic, RichardWeber, MichaelDOI: info:10.3847/1538-4357/aba516v. 89968
Dupree, Andrea K., Strassmeier, Klaus G., Matthews, Lynn D., Uitenbroek, Han, Calderwood, Thomas, Granzer, Thomas, Guinan, Edward F., Leike, Reimar, Montargès, Miguel, Richards, Anita M. S., Wasatonic, Richard, and Weber, Michael. 2020. "Spatially Resolved Ultraviolet Spectroscopy of the Great Dimming of Betelgeuse." The Astrophysical Journal 899:68. https://doi.org/10.3847/1538-4357/aba516
ID: 157665
Type: article
Authors: Dupree, Andrea K.; Strassmeier, Klaus G.; Matthews, Lynn D.; Uitenbroek, Han; Calderwood, Thomas; Granzer, Thomas; Guinan, Edward F.; Leike, Reimar; Montargès, Miguel; Richards, Anita M. S.; Wasatonic, Richard; Weber, Michael
Abstract: The bright supergiant Betelgeuse (Alpha Orionis, HD 39801) experienced a visual dimming during 2019 December and the first quarter of 2020, reaching an historic minimum 2020 February 7-13. During 2019 September-November, prior to the optical dimming event, the photosphere was expanding. At the same time, spatially resolved ultraviolet spectra using the Hubble Space Telescope/Space Telescope Imaging Spectrograph revealed a substantial increase in the ultraviolet spectrum and Mg II line emission from the chromosphere over the southern hemisphere of the star. Moreover, the temperature and electron density inferred from the spectrum and C II diagnostics also increased in this hemisphere. These changes happened prior to the Great Dimming Event. Variations in the Mg II k-line profiles suggest material moved outwards in response to the passage of a pulse or acoustic shock from 2019 September through November. It appears that this extraordinary outflow of material from the star, likely initiated by convective photospheric elements, was enhanced by the coincidence with the outward motions in this phase of the ∼400 day pulsation cycle. These ultraviolet observations appear to provide the connecting link between the known large convective cells in the photosphere and the mass ejection event that cooled to form the dust cloud in the southern hemisphere imaged in 2019 December, and led to the exceptional optical dimming of Betelgeuse in 2020 February.
The Most Metal-poor Stars in Omega Centauri (NGC 5139)Johnson, Christian I.Dupree, Andrea K.Mateo, MarioBailey, John I.,IIIOlszewski, Edward W.Walker, Matthew G.DOI: info:10.3847/1538-3881/ab8819v. 159254
Johnson, Christian I., Dupree, Andrea K., Mateo, Mario, Bailey, John I.,III, Olszewski, Edward W., and Walker, Matthew G. 2020. "The Most Metal-poor Stars in Omega Centauri (NGC 5139)." The Astronomical Journal 159:254. https://doi.org/10.3847/1538-3881/ab8819
ID: 157666
Type: article
Authors: Johnson, Christian I.; Dupree, Andrea K.; Mateo, Mario; Bailey, John I.,III; Olszewski, Edward W.; Walker, Matthew G.
Abstract: The most massive and complex globular clusters in the Galaxy are thought to have originated as the nuclear cores of now tidally disrupted dwarf galaxies, but the connection between globular clusters and dwarf galaxies is tenuous with the M54/Sagittarius system representing the only unambiguous link. The globular cluster Omega Centauri (ω Cen) is more massive and chemically diverse than M 54, and is thought to have been the nuclear star cluster of either the Sequoia or Gaia-Enceladus galaxy. Local Group dwarf galaxies with masses equivalent to these systems often host significant populations of very metal-poor stars ([Fe/H] This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.
Rydberg spectrum of a single trapped Ca+ ion: A Floquet analysisPawlak, MariuszSadeghpour, Hossein R.DOI: info:10.1103/PhysRevA.101.052510v. 101052510
Pawlak, Mariusz and Sadeghpour, Hossein R. 2020. "Rydberg spectrum of a single trapped Ca+ ion: A Floquet analysis." Physical Review A 101:052510. https://doi.org/10.1103/PhysRevA.101.052510
ID: 157667
Type: article
Authors: Pawlak, Mariusz; Sadeghpour, Hossein R.
Abstract: We compute the Rydberg spectrum of a single Ca+ ion in a Paul trap by incorporating various internal and external coupling terms of the ion to the trap in the Hamiltonian. The coupling terms include spin-orbit coupling in Ca+, charge (electron and ionic core) coupling to the radio frequency and static fields, ion-electron coupling in the Paul trap, and ion center-of-mass coupling. The electronic Rydberg states are precisely described by a one-electron model potential for e-+Ca2 + , and accurate eigenenergies, quantum defect parameters, and static and tensor polarizabilities for a number of excited Rydberg states are obtained. The time-periodic rf Hamiltonian is expanded in the Floquet basis, and the trapping-field-broadened Rydberg lines are compared with recent observations of Ca+(23 P ) and Ca+(52 F ) Rydberg lines.
Non-Maxwellian rate coefficients for electron and ion collisions in Rydberg plasmas: implications for excitation and ionizationVrinceanu, DanielOnofrio, RobertoSadeghpour, Hossein R.DOI: info:10.1017/S0022377820000513v. 86845860301
Vrinceanu, Daniel, Onofrio, Roberto, and Sadeghpour, Hossein R. 2020. "Non-Maxwellian rate coefficients for electron and ion collisions in Rydberg plasmas: implications for excitation and ionization." Journal of Plasma Physics 86:845860301. https://doi.org/10.1017/S0022377820000513
ID: 157668
Type: article
Authors: Vrinceanu, Daniel; Onofrio, Roberto; Sadeghpour, Hossein R.
Abstract: Scattering phenomena between charged particles and highly excited Rydberg atoms are of critical importance in many processes in plasma physics and astrophysics. While a Maxwell-Boltzmann (MB) energy distribution for the charged particles is often assumed for calculations of collisional rate coefficients, in this contribution we relax this assumption and use two different energy distributions, a bimodal MB distribution and a $\unicode[STIX]{x1D705}$-distribution. Both variants share a high-energy tails occurring with higher probability than the corresponding MB distribution. The high-energy tail may significantly affect rate coefficients for various processes. We focus the analysis to specific situations by showing the dependence of the rate coefficients on the principal quantum number of hydrogen atoms in $n$-changing collisions with electrons in the excitation and ionization channels and in a temperature range relevant to the divertor region of a tokamak device. We finally discuss the implications for diagnostics of laboratory plasmas.
μ⋆ masses: weak-lensing calibration of the Dark Energy Survey Year 1 redMaPPer clusters using stellar massesPereira, M. E. S.Palmese, A.Varga, T. N.McClintock, T.Soares-Santos, M.Burgad, J.Annis, J.Farahi, A.Lin, H.Choi, A.DeRose, J.Esteves, J.Gatti, M.Gruen, D.Hartley, W. G.Hoyle, B.Jeltema, T.MacCrann, N.Roodman, A.Sánchez, C.Shin, T.von der Linden, A.Zuntz, J.Abbott, T. M. C.Aguena, M.Avila, S.Bertin, E.Bhargava, S.Bridle, S. L.Brooks, D.Burke, D. L.Carnero Rosell, A.Carrasco Kind, M.Carretero, J.Costanzi, M.da Costa, L. N.Desai, S.Diehl, H. T.Dietrich, J. P.Doel, P.Estrada, J.Everett, S.Flaugher, B.Fosalba, P.Frieman, J.García-Bellido, J.Gaztanaga, E.Gerdes, D. W.Gruendl, R. A.Gschwend, J.Gutierrez, G.Hinton, S. R.Hollowood, D. L.Honscheid, K.James, David J.Kuehn, K.Kuropatkin, N.Lahav, O.Lima, M.Maia, M. A. G.March, M.Marshall, J. L.Melchior, P.Menanteau, F.Miquel, R.Ogando, R. L. C.Paz-Chinchón, F.Plazas, A. A.Romer, A. K.Sanchez, E.Scarpine, V.Schubnell, M.Serrano, S.Sevilla-Noarbe, I.Smith, M.Suchyta, E.Swanson, M. E. C.Tarle, G.Wechsler, R. H.Weller, J.Zhang, Y.DES CollaborationDOI: info:10.1093/mnras/staa2687v. 4985450–5467
Pereira, M. E. S., Palmese, A., Varga, T. N., McClintock, T., Soares-Santos, M., Burgad, J., Annis, J., Farahi, A., Lin, H., Choi, A., DeRose, J., Esteves, J., Gatti, M., Gruen, D., Hartley, W. G., Hoyle, B., Jeltema, T., MacCrann, N., Roodman, A., Sánchez, C., Shin, T., von der Linden, A., Zuntz, J., Abbott, T. M. C., Aguena, M. et al. 2020. "μ masses: weak-lensing calibration of the Dark Energy Survey Year 1 redMaPPer clusters using stellar masses." Monthly Notices of the Royal Astronomical Society 498:5450– 5467. https://doi.org/10.1093/mnras/staa2687
ID: 157669
Type: article
Authors: Pereira, M. E. S.; Palmese, A.; Varga, T. N.; McClintock, T.; Soares-Santos, M.; Burgad, J.; Annis, J.; Farahi, A.; Lin, H.; Choi, A.; DeRose, J.; Esteves, J.; Gatti, M.; Gruen, D.; Hartley, W. G.; Hoyle, B.; Jeltema, T.; MacCrann, N.; Roodman, A.; Sánchez, C.; Shin, T.; von der Linden, A.; Zuntz, J.; Abbott, T. M. C.; Aguena, M.; Avila, S.; Bertin, E.; Bhargava, S.; Bridle, S. L.; Brooks, D.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Costanzi, M.; da Costa, L. N.; Desai, S.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Estrada, J.; Everett, S.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gaztanaga, E.; Gerdes, D. W.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Hinton, S. R.; Hollowood, D. L.; Honscheid, K.; James, David J.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Lima, M.; Maia, M. A. G.; March, M.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Miquel, R.; Ogando, R. L. C.; Paz-Chinchón, F.; Plazas, A. A.; Romer, A. K.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Serrano, S.; Sevilla-Noarbe, I.; Smith, M.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Wechsler, R. H.; Weller, J.; Zhang, Y.; DES Collaboration
Abstract: We present the weak-lensing mass calibration of the stellar-mass-based μ mass proxy for redMaPPer galaxy clusters in the Dark Energy Survey Year 1. For the first time, we are able to perform a calibration of μ at high redshifts, z > 0.33. In a blinded analysis, we use ∼6000 clusters split into 12 subsets spanning the ranges 0.1 ≤ z at high redshifts, z > 0.33. In a blinded analysis, we use ∼6000 clusters split into 12 subsets spanning the ranges 0.1 ≤ z up to ${\sim} 5.5 \times 10^{13} \, \mathrm{M}_{\odot }$ , and infer the average masses of these subsets through modelling of their stacked weak-lensing signal. In our model, we account for the following sources of systematic uncertainty: shear measurement and photometric redshift errors, miscentring, cluster-member contamination of the source sample, deviations from the Navarro-Frenk-White halo profile, halo triaxiality, and projection effects. We use the inferred masses to estimate the joint mass-μ-z scaling relation given by $\langle M_{200c} | \mu _{\star },z \rangle = M_0 (\mu _{\star }/5.16\times 10^{12} \, \mathrm{M_{\odot }})^{F_{\mu _{\star }}} ((1+z)/1.35)^{G_z}$ . We find $M_0= (1.14 \pm 0.07) \times 10^{14} \, \mathrm{M_{\odot }}$ with $F_{\mu _{\star }}= 0.76 \pm 0.06$ and Gz = -1.14 ± 0.37. We discuss the use of μ as a complementary mass proxy to the well-studied richness λ for: (i) exploring the regimes of low z, λ < 20 and high λ, z ∼ 1; and (ii) testing systematics such as projection effects for applications in cluster cosmology.
Detection of Interstellar HC4NC and an Investigation of Isocyanopolyyne Chemistry under TMC-1 ConditionsXue, CiWillis, Eric R.Loomis, Ryan A.Lee, Kin Long KelvinBurkhardt, Andrew M.Shingledecker, Christopher N.Charnley, Steven B.Cordiner, Martin A.Kalenskii, SergeiMcCarthy, Michael C.Herbst, EricRemijan, Anthony J.McGuire, Brett A.DOI: info:10.3847/2041-8213/aba631v. 900L9
Xue, Ci, Willis, Eric R., Loomis, Ryan A., Lee, Kin Long Kelvin, Burkhardt, Andrew M., Shingledecker, Christopher N., Charnley, Steven B., Cordiner, Martin A., Kalenskii, Sergei, McCarthy, Michael C., Herbst, Eric, Remijan, Anthony J., and McGuire, Brett A. 2020. "Detection of Interstellar HC4NC and an Investigation of Isocyanopolyyne Chemistry under TMC-1 Conditions." The Astrophysical Journal 900:L9. https://doi.org/10.3847/2041-8213/aba631
ID: 157670
Type: article
Authors: Xue, Ci; Willis, Eric R.; Loomis, Ryan A.; Lee, Kin Long Kelvin; Burkhardt, Andrew M.; Shingledecker, Christopher N.; Charnley, Steven B.; Cordiner, Martin A.; Kalenskii, Sergei; McCarthy, Michael C.; Herbst, Eric; Remijan, Anthony J.; McGuire, Brett A.
Abstract: We report an astronomical detection of HC4NC for the first time in the interstellar medium with the Green Bank Telescope toward the TMC-1 molecular cloud with a minimum significance of 10.5σ. The total column density and excitation temperature of HC4NC are determined to be ${3.29}_{-1.20}^{+8.60}\times {10}^{11}$ cm-2 and ${6.7}_{-0.3}^{+0.3}\ {\rm{K}}$ , respectively, using Markov chain Monte Carlo analysis. In addition to HC4NC, HCCNC is distinctly detected whereas no clear detection of HC6NC is made. We propose that the dissociative recombination of the protonated cyanopolyyne, HC5NH+, and the protonated isocyanopolyyne, HC4NCH+, are the main formation mechanisms for HC4NC while its destruction is dominated by reactions with simple ions and atomic carbon. With the proposed chemical networks, the observed abundances of HC4NC and HCCNC are reproduced satisfactorily.
Structural Evolution in Massive Galaxies at z ∼ 2Tadaki, Ken-ichiBelli, SirioBurkert, AndreasDekel, AvishaiFörster Schreiber, Natascha M.Genzel, ReinhardHayashi, MasaoHerrera-Camus, RodrigoKodama, TadayukiKohno, KotaroKoyama, YuseiLee, Minju M.Lutz, DieterMowla, LamiyaNelson, Erica J.Renzini, AlvioSuzuki, Tomoko L.Tacconi, Linda J.Übler, HannahWisnioski, EmilyWuyts, StijnDOI: info:10.3847/1538-4357/abaf4av. 90174
Tadaki, Ken-ichi, Belli, Sirio, Burkert, Andreas, Dekel, Avishai, Förster Schreiber, Natascha M., Genzel, Reinhard, Hayashi, Masao, Herrera-Camus, Rodrigo, Kodama, Tadayuki, Kohno, Kotaro, Koyama, Yusei, Lee, Minju M., Lutz, Dieter, Mowla, Lamiya, Nelson, Erica J., Renzini, Alvio, Suzuki, Tomoko L., Tacconi, Linda J., Übler, Hannah, Wisnioski, Emily, and Wuyts, Stijn. 2020. "Structural Evolution in Massive Galaxies at z ∼ 2." The Astrophysical Journal 901:74. https://doi.org/10.3847/1538-4357/abaf4a
ID: 157671
Type: article
Authors: Tadaki, Ken-ichi; Belli, Sirio; Burkert, Andreas; Dekel, Avishai; Förster Schreiber, Natascha M.; Genzel, Reinhard; Hayashi, Masao; Herrera-Camus, Rodrigo; Kodama, Tadayuki; Kohno, Kotaro; Koyama, Yusei; Lee, Minju M.; Lutz, Dieter; Mowla, Lamiya; Nelson, Erica J.; Renzini, Alvio; Suzuki, Tomoko L.; Tacconi, Linda J.; Übler, Hannah; Wisnioski, Emily; Wuyts, Stijn
Abstract: We present 0"2 resolution Atacama Large Millimeter/submillimeter Array (ALMA) observations at 870 μm in a stellar mass-selected sample of 85 massive ( ${M}_{\star }\gt {10}^{11}\,{M}_{\odot }$ ) star-forming galaxies (SFGs) at $z=1.9\mbox{--}2.6$ in the CANDELS/3D-Hubble Space Telescope fields of UDS and GOODS-S. We measure the effective radius of the rest-frame far-infrared (FIR) emission for 62 massive SFGs. They are distributed over wide ranges of FIR size from ${R}_{{\rm{e}},\mathrm{FIR}}=0.4\,\mathrm{kpc}$ to ${R}_{{\rm{e}},\mathrm{FIR}}=6\,\mathrm{kpc}$ . The effective radius of the FIR emission is smaller by a factor of ${2.3}_{-1.0}^{+1.9}$ than the effective radius of the optical emission and is smaller by a factor of ${1.9}_{-1.0}^{+1.9}$ than the half-mass radius. Taking into account potential extended components, the FIR size would change only by ∼10%. By combining the spatial distributions of the FIR and optical emission, we investigate how galaxies change the effective radius of the optical emission and the stellar mass within a radius of 1 kpc, ${M}_{1\mathrm{kpc}}$ . The compact starburst puts most of the massive SFGs on the mass-size relation for quiescent galaxies (QGs) at z ∼ 2 within 300 Myr if the current star formation activity and its spatial distribution are maintained. We also find that within 300 Myr, ∼38% of massive SFGs can reach the central mass of ${M}_{1\mathrm{kpc}}={10}^{10.5}\,{M}_{\odot }$ , which is around the boundary between massive SFGs and QGs. These results suggest an outside-in transformation scenario in which a dense core is formed at the center of a more extended disk, likely via dissipative in-disk inflows. Synchronized observations at ALMA 870 μm and James Webb Space Telescope 3-4 μm will explicitly verify this scenario.
Late-time Circumstellar Interaction of SN 2017eaw in NGC 6946Weil, Kathryn E.Fesen, Robert A.Patnaude, Daniel J.Milisavljevic, DanDOI: info:10.3847/1538-4357/aba4b1v. 90011
Weil, Kathryn E., Fesen, Robert A., Patnaude, Daniel J., and Milisavljevic, Dan. 2020. "Late-time Circumstellar Interaction of SN 2017eaw in NGC 6946." The Astrophysical Journal 900:11. https://doi.org/10.3847/1538-4357/aba4b1
ID: 157672
Type: article
Authors: Weil, Kathryn E.; Fesen, Robert A.; Patnaude, Daniel J.; Milisavljevic, Dan
Abstract: SN 2017eaw, the tenth supernova observed in NGC 6946, was a normal Type II-P supernova with an estimated 11-13 M red supergiant progenitor. Here we present nebular-phase spectra of SN 2017eaw at +545 and +900 days post-max, extending approximately 50-400 days past the epochs of previously published spectra. While the +545 day spectrum is similar to spectra taken between days +400 and +493, the +900 day spectrum shows dramatic changes both in spectral features and emission-line profiles. The Hα emission is flat-topped and boxlike with sharp blue and red profile velocities of ≃-8000 and +7500 km s-1. These late-time spectral changes indicate strong circumstellar interaction with a mass-loss shell, expelled ∼1700 yr before explosion. SN 2017eaw's +900 day spectrum is similar to those seen for SN 2004et and SN 2013ej observed 2-3 yr after explosion. We discuss the importance of late-time monitoring of bright SNe II-P and the nature of presupernova mass-loss events for SN II-P evolution.
MINESweeper: Spectrophotometric Modeling of Stars in the Gaia EraCargile, Phillip A.Conroy, CharlieJohnson, Benjamin D.Ting, Yuan-SenBonaca, AnaDotter, AaronSpeagle, Joshua S.DOI: info:10.3847/1538-4357/aba43bv. 90028
Cargile, Phillip A., Conroy, Charlie, Johnson, Benjamin D., Ting, Yuan-Sen, Bonaca, Ana, Dotter, Aaron, and Speagle, Joshua S. 2020. "MINESweeper: Spectrophotometric Modeling of Stars in the Gaia Era." The Astrophysical Journal 900:28. https://doi.org/10.3847/1538-4357/aba43b
ID: 157673
Type: article
Authors: Cargile, Phillip A.; Conroy, Charlie; Johnson, Benjamin D.; Ting, Yuan-Sen; Bonaca, Ana; Dotter, Aaron; Speagle, Joshua S.
Abstract: We present MINESweeper, a tool to measure stellar parameters by jointly fitting observed spectra and broadband photometry to model isochrones and spectral libraries. This approach enables the measurement of spectrophotometric distances, in addition to stellar parameters such as Teff, $\mathrm{log}g$, [Fe/H], [α/Fe], and radial velocity. MINESweeper employs a Bayesian framework and can easily incorporate a variety of priors, including Gaia parallaxes. Mock data are fit in order to demonstrate how the precision of derived parameters depends on evolutionary phase and signal-to-noise ratio. We then fit a selection of data in order to validate the model outputs. Fits to a variety of benchmark stars including Procyon, Arcturus, and the Sun result in derived stellar parameters that are in good agreement with the literature. We then fit combined spectra and photometry of stars in the open and globular clusters M92, M13, M3, M107, M71, and M67. Derived distances, [Fe/H], [α/Fe], and $\mathrm{log}g$-Teff relations are in overall good agreement with literature values, although there are trends between metallicity and $\mathrm{log}g$ within clusters that point to systematic uncertainties at the ≍0.1 dex level. Finally, we fit a large sample of stars from the H3 Spectroscopic Survey in which high-quality Gaia parallaxes are also available. These stars are fit without the Gaia parallaxes so that the geometric parallaxes can serve as an independent test of the spectrophotometric distances. Comparison between the two reveals good agreement within their formal uncertainties after accounting for the Gaia zero-point uncertainties.
Evidence from the H3 Survey That the Stellar Halo Is Entirely Comprised of SubstructureNaidu, Rohan P.Conroy, CharlieBonaca, AnaJohnson, Benjamin D.Ting, Yuan-SenCaldwell, NelsonZaritsky, DennisCargile, Phillip A.DOI: info:10.3847/1538-4357/abaef4v. 90148
Naidu, Rohan P., Conroy, Charlie, Bonaca, Ana, Johnson, Benjamin D., Ting, Yuan-Sen, Caldwell, Nelson, Zaritsky, Dennis, and Cargile, Phillip A. 2020. "Evidence from the H3 Survey That the Stellar Halo Is Entirely Comprised of Substructure." The Astrophysical Journal 901:48. https://doi.org/10.3847/1538-4357/abaef4
ID: 157674
Type: article
Authors: Naidu, Rohan P.; Conroy, Charlie; Bonaca, Ana; Johnson, Benjamin D.; Ting, Yuan-Sen; Caldwell, Nelson; Zaritsky, Dennis; Cargile, Phillip A.
Abstract: In the ΛCDM paradigm, the Galactic stellar halo is predicted to harbor the accreted debris of smaller systems. To identify these systems, the H3 Spectroscopic Survey, combined with Gaia, is gathering 6D phase-space and chemical information in the distant Galaxy. Here we present a comprehensive inventory of structure within 50 kpc from the Galactic center using a sample of 5684 giants at $| b| \gt 40^\circ $ and $| Z| \gt 2\,\mathrm{kpc}$ . We identify known structures including the high-α disk, the in situ halo (disk stars heated to eccentric orbits), Sagittarius (Sgr), Gaia-Sausage-Enceladus (GSE), the Helmi Streams, Sequoia, and Thamnos. Additionally, we identify the following new structures: (i) Aleph ([Fe/H] = -0.5), a low-eccentricity structure that rises a surprising 10 kpc off the plane, (ii) and (iii) Arjuna ([Fe/H] = -1.2) and I'itoi ([Fe/H] 80% of the halo is built by two massive (M ∼ 108-109M) accreted dwarfs: GSE ([Fe/H] = -1.2) within 25 kpc and Sgr ([Fe/H] = -1.0) beyond 25 kpc. This explains the relatively high overall metallicity of the halo ([Fe/H] ≍ -1.2). We attribute ≳95% of the sample to one of the listed structures, pointing to a halo built entirely from accreted dwarfs and heating of the disk.
Timing the Early Assembly of the Milky Way with the H3 SurveyBonaca, AnaConroy, CharlieCargile, Phillip A.Naidu, Rohan P.Johnson, Benjamin D.Zaritsky, DennisTing, Yuan-SenCaldwell, NelsonHan, Jiwon Jessevan Dokkum, PieterDOI: info:10.3847/2041-8213/ab9caav. 897L18
Bonaca, Ana, Conroy, Charlie, Cargile, Phillip A., Naidu, Rohan P., Johnson, Benjamin D., Zaritsky, Dennis, Ting, Yuan-Sen, Caldwell, Nelson, Han, Jiwon Jesse, and van Dokkum, Pieter. 2020. "Timing the Early Assembly of the Milky Way with the H3 Survey." The Astrophysical Journal 897:L18. https://doi.org/10.3847/2041-8213/ab9caa
ID: 157675
Type: article
Authors: Bonaca, Ana; Conroy, Charlie; Cargile, Phillip A.; Naidu, Rohan P.; Johnson, Benjamin D.; Zaritsky, Dennis; Ting, Yuan-Sen; Caldwell, Nelson; Han, Jiwon Jesse; van Dokkum, Pieter
Abstract: The archeological record of stars in the Milky Way opens a uniquely detailed window into the early formation and assembly of galaxies. Here we use 11,000 main-sequence turn-off stars with well-measured ages, $[\mathrm{Fe}/{\rm{H}}]$ , $[\alpha /\mathrm{Fe}]$ , and orbits from the H3 Survey and Gaia to time the major events in the early Galaxy. Located beyond the Galactic plane, $1\lesssim | Z| /\mathrm{kpc}\lesssim 4$ , this sample contains three chemically distinct groups: a low-metallicity population, and low-α and high-α groups at higher metallicity. The age and orbit distributions of these populations show that (1) the high-α group, which includes both disk stars and the in situ halo, has a star formation history independent of eccentricity that abruptly truncated 8.3 ± 0.1 Gyr ago (z ≃ 1); (2) the low-metallicity population, which we identify as the accreted stellar halo, is on eccentric orbits and its star formation truncated $10.2{.}_{-0.1}^{+0.2}$ Gyr ago (z ≃ 2); (3) the low-α population is primarily on low-eccentricity orbits and the bulk of its stars formed less than 8 Gyr ago. These results suggest a scenario in which the Milky Way accreted a satellite galaxy at z ≍ 2 that merged with the early disk by z ≍ 1. This merger truncated star formation in the early high-α disk and perturbed a fraction of that disk onto halo-like orbits. The merger enabled the formation of a chemically distinct, low-α disk at z ≲ 1. The lack of any stars on halo-like orbits at younger ages indicates that this event was the last significant disturbance to the Milky Way disk.
Chemistry Along Accretion Streams in a Viscously Evolving Protoplanetary DiskPrice, Ellen M.Cleeves, L. IlsedoreÖberg, Karin I.DOI: info:10.3847/1538-4357/ab5fd4v. 890154
Price, Ellen M., Cleeves, L. Ilsedore, and Öberg, Karin I. 2020. "Chemistry Along Accretion Streams in a Viscously Evolving Protoplanetary Disk." The Astrophysical Journal 890:154. https://doi.org/10.3847/1538-4357/ab5fd4
ID: 157676
Type: article
Authors: Price, Ellen M.; Cleeves, L. Ilsedore; Öberg, Karin I.
Abstract: The composition of a protoplanetary disk is set by a combination of interstellar inheritance and gas and grain surface chemical reactions within the disk. The survival of inherited molecules, as well as the disk in situ chemistry depends on the local temperature, density and irradiation environment, which can change over time due to stellar and disk evolution, as well as transport in the disk. We address one aspect of this coupling between the physical and chemical evolution in disks by following accretion streamlines of gas and small grains in the disk midplane, while simultaneously taking the evolving star into account. This approach is computationally efficient and enables us to take into account changing physical conditions without reducing the chemical network. We find that many species are enhanced in the inner disk midplane in the dynamic model due to inward transport of cosmic-ray driven chemical products, resulting in, e.g., orders of magnitude hydrocarbon enhancements at 1 au, compared to a static disk. For several other chemical families, there is no difference between the static and dynamic models, indicative of a robust chemical reset, while yet others show differences between static and dynamic models that depend on complex interactions between physics and chemistry during the inward track. The importance of coupling dynamics and chemistry when modeling the chemical evolution of protoplanetary disks thus depends on what chemistry is of interest.
Polarized emission by aligned grains in the Mie regime: Application to protoplanetary disks observed by ALMAGuillet, V.Girart, J. M.Maury, Anaëlle J.Alves, F. O.DOI: info:10.1051/0004-6361/201937314v. 634L15
Guillet, V., Girart, J. M., Maury, Anaëlle J., and Alves, F. O. 2020. "Polarized emission by aligned grains in the Mie regime: Application to protoplanetary disks observed by ALMA." Astronomy and Astrophysics 634:L15. https://doi.org/10.1051/0004-6361/201937314
ID: 157677
Type: article
Authors: Guillet, V.; Girart, J. M.; Maury, Anaëlle J.; Alves, F. O.
Abstract: Context. The azimuthal polarization patterns observed in some protoplanetary disks by the Atacama Large Millimetre Array (ALMA) at millimeter wavelengths have raised doubts about whether they are truly produced by dust grains that are aligned with the magnetic field lines. These conclusions were based on the calculations of dust polarized emission in the Rayleigh regime, that is, for grain sizes that are much smaller than the wavelength. However, the grain size in such disks is typically estimated to be in the range of 0.1-1 mm from independent observations.
Aims: We study the dust polarization properties of aligned grains in emission in the Mie regime, that is, when the mean grain size approaches the wavelength.
Methods: By using the T-MATRIX and DustEM codes, we computed the spectral dependence of the polarization fraction in emission for grains in perfect spinning alignment for various grain size distributions. We restricted our study to weakly-elongated oblate and prolate grains of astrosilicate composition that have a mean size ranging from 10 μm to 1 mm.
Results: In the submillimeter and millimeter wavelength range, the polarization by B-field aligned grains becomes negative for grains larger than ∼250 μm, meaning that the polarization vector becomes parallel to the B-field. The transition from the positive to the negative polarization occurs at a wavelength of λ ∼ 1 mm. The regime of negative polarization does not exist for grains that are smaller than ∼100 μm.
Conclusions: When using realistic grain size distributions for disks with grains up to the submillimeter sizes, the polarization direction of thermal emission by aligned grains is shown to be parallel to the direction of the magnetic field over a significant fraction of the wavelengths typically used to observe young protoplanetary disks. This property may explain the peculiar azimuthal orientation of the polarization vectors in some of the disks observed with ALMA and attest to the conserved ability of dust polarized emission to trace the magnetic field in disks.
Full-Array Noise Performance of Deployment-Grade SuperSpec mm-Wave On-Chip SpectrometersKarkare, K. S.Barry, P. S.Bradford, C. M.Chapman, S.Doyle, S.Glenn, J.Gordon, S.Hailey-Dunsheath, S.Janssen, R. M. J.Kovács, AttilaLeDuc, H. G.Mauskopf, P.McGeehan, R.Redford, J.Shirokoff, E.Tucker, C.Wheeler, J.Zmuidzinas, J.DOI: info:10.1007/s10909-020-02407-4v. 199849–857
Karkare, K. S., Barry, P. S., Bradford, C. M., Chapman, S., Doyle, S., Glenn, J., Gordon, S., Hailey-Dunsheath, S., Janssen, R. M. J., Kovács, Attila, LeDuc, H. G., Mauskopf, P., McGeehan, R., Redford, J., Shirokoff, E., Tucker, C., Wheeler, J., and Zmuidzinas, J. 2020. "Full-Array Noise Performance of Deployment-Grade SuperSpec mm-Wave On-Chip Spectrometers." Journal of Low Temperature Physics 199:849– 857. https://doi.org/10.1007/s10909-020-02407-4
ID: 157678
Type: article
Authors: Karkare, K. S.; Barry, P. S.; Bradford, C. M.; Chapman, S.; Doyle, S.; Glenn, J.; Gordon, S.; Hailey-Dunsheath, S.; Janssen, R. M. J.; Kovács, Attila; LeDuc, H. G.; Mauskopf, P.; McGeehan, R.; Redford, J.; Shirokoff, E.; Tucker, C.; Wheeler, J.; Zmuidzinas, J.
Abstract: SuperSpec is an on-chip filter bank spectrometer designed for wideband moderate-resolution spectroscopy at millimeter wavelengths, employing TiN kinetic inductance detectors. SuperSpec technology will enable large-format spectroscopic integral field units suitable for high-redshift line intensity mapping and multi-object spectrographs. In previous results, we have demonstrated noise performance in individual detectors suitable for photon noise-limited ground-based observations at excellent mm-wave sites. In these proceedings, we present the noise performance of a full R ∼275 spectrometer measured using deployment-ready RF hardware and software. We report typical noise equivalent powers through the full device of ∼3 ×10-16 WHz-1/2 at expected sky loadings, which are photon noise dominated. Based on these results, we plan to deploy a six-spectrometer demonstration instrument to the Large Millimeter Telescope in early 2020.
Ultradiffuse Galaxies in the Coma Cluster: Probing Their Origin and AGN Occupation FractionKovács, Orsolya E.Bogdán, ÁkosCanning, Rebecca E. A.DOI: info:10.3847/1538-4357/aba04fv. 898164
Kovács, Orsolya E., Bogdán, Ákos, and Canning, Rebecca E. A. 2020. "Ultradiffuse Galaxies in the Coma Cluster: Probing Their Origin and AGN Occupation Fraction." The Astrophysical Journal 898:164. https://doi.org/10.3847/1538-4357/aba04f
ID: 157679
Type: article
Authors: Kovács, Orsolya E.; Bogdán, Ákos; Canning, Rebecca E. A.
Abstract: Ultradiffuse galaxies (UDGs) exhibit low surface brightness, but their optical extent is comparable to that of Milky Way-type galaxies. In this work, we utilize Chandra X-ray observations of 404 UDGs in the Coma cluster and address two crucial goals. First, we constrain the formation scenario of UDGs by probing the X-ray emission originating from diffuse gas and from the population of unresolved low-mass X-ray binaries (LMXBs) residing in globular clusters (GCs). It is expected that both the luminosity of the hot gas and the number of GCs, and hence the luminosity from GC-LMXBs, are proportional to the total mass of the dark matter halo. We do not detect statistically significant emission from the hot gas or from GC-LMXBs. The upper limits on the X-ray luminosities suggest that the bulk of the UDGs reside in low-mass dark matter halos, implying that they are genuine dwarf galaxies. This conclusion agrees with our previous results obtained for isolated UDGs, arguing that UDGs are a homogeneous population of galaxies. Second, we constrain the AGN occupation fraction of UDGs, i.e., the fraction of UDGs that are occupied by an active galactic nucleus, for the first time. To this end, we cross-correlate the position of detected X-ray sources in the Coma cluster with the position of UDGs. We identify two UDGs that have a luminous X-ray source at 3"0 and 3"2 from their center, which could be off-center AGNs. However, Monte Carlo simulations suggest that one of these sources could be the result of spatial coincidence with a background AGN. Therefore, we place an upper limit of ≲0.5% on the AGN occupation fraction of UDGs.
(Non)radial Solar Wind Propagation through the HeliosphereNěmeček, ZdeněkĎurovcová, TerezaŠafránková, JanaRichardson, John D.Šimůnek, JiříStevens, Michael L.DOI: info:10.3847/2041-8213/ab9ff7v. 897L39
Němeček, Zdeněk, Ďurovcová, Tereza, Šafránková, Jana, Richardson, John D., Šimůnek, Jiří, and Stevens, Michael L. 2020. "(Non)radial Solar Wind Propagation through the Heliosphere." The Astrophysical Journal 897:L39. https://doi.org/10.3847/2041-8213/ab9ff7
ID: 157680
Type: article
Authors: Němeček, Zdeněk; Ďurovcová, Tereza; Šafránková, Jana; Richardson, John D.; Šimůnek, Jiří; Stevens, Michael L.
Abstract: The solar wind nonradial velocity components observed beyond the Alfvén point are usually attributed to waves, the interaction of different streams, or other transient phenomena. However, Earth-orbiting spacecraft as well as monitors at L1 indicate systematic deviations of the wind velocity from the radial direction. Since these deviations are of the order of several degrees, the calibration of the instruments is often questioned. This paper investigates for the first time the evolution of nonradial components of the solar wind flow along the path from ≍0.17 to 10 au. A comparison of observations at 1 au with those closer to or farther from the Sun based on measurements of many spacecraft at different locations in the heliosphere (Parker Solar Probe, Helios 1 and 2, Wind, Advanced Composition Explorer, Spektr-R, Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun (ARTEMIS) probes, Mars Atmosphere and Volatile Evolution (MAVEN), Voyagers 1 and 2) shows that (I) the average values of nonradial components are not zero and vary in a systematic manner with the distance from the Sun and (II) their values significantly depend on the solar wind radial velocity.
Credit Lost: Two Decades of Software Citation in AstronomyBouquin, Daina R.Chivvis, Daniel A.Henneken, EdwinLockhart, KellyMuench, AugustKoch, JenniferDOI: info:10.3847/1538-4365/ab7be6v. 2498
Bouquin, Daina R., Chivvis, Daniel A., Henneken, Edwin, Lockhart, Kelly, Muench, August, and Koch, Jennifer. 2020. "Credit Lost: Two Decades of Software Citation in Astronomy." The Astrophysical Journal Supplement Series 249:8. https://doi.org/10.3847/1538-4365/ab7be6
ID: 157681
Type: article
Authors: Bouquin, Daina R.; Chivvis, Daniel A.; Henneken, Edwin; Lockhart, Kelly; Muench, August; Koch, Jennifer
Abstract: Software has been a crucial contributor to scientific progress in astronomy for decades, but practices that enable machine-actionable citations have not been consistently applied to software itself. Instead, software citation behaviors developed independently from standard publication mechanisms and policies, resulting in human-readable citations that remain hidden over time and that cannot represent the influence software has had in the field. These historical software citation behaviors need to be understood in order to improve software citation guidance and develop relevant publishing practices that fully support the astronomy community. To this end, a 23 year retrospective analysis of software citation practices in astronomy was developed. Astronomy publications were mined for 410 aliases associated with nine software packages and analyzed to identify past practices and trends that prevent software citations from benefiting software authors.
Measurements of linear polarization of satellite transitions from Li- and Be-like Ar ionsGall, Amy C.DiptiBuechele, S. W.Sanders, S.Szabo, C. I.Silwal, R.Ralchenko, YuBrickhouse, Nancy S.Takacs, E.DOI: info:10.1088/1361-6455/ab8effv. 53145004
Gall, Amy C., Dipti, Buechele, S. W., Sanders, S., Szabo, C. I., Silwal, R., Ralchenko, Yu, Brickhouse, Nancy S., and Takacs, E. 2020. "Measurements of linear polarization of satellite transitions from Li- and Be-like Ar ions." Journal of Physics B Atomic Molecular Physics 53:145004. https://doi.org/10.1088/1361-6455/ab8eff
ID: 157682
Type: article
Authors: Gall, Amy C.; Dipti; Buechele, S. W.; Sanders, S.; Szabo, C. I.; Silwal, R.; Ralchenko, Yu; Brickhouse, Nancy S.; Takacs, E.
Abstract: Non-thermal electron distributions, such as beams of electrons, are found in many laboratory and astrophysical plasma sources and can produce anisotropic and polarized emission. Theories used to model the emission require sublevel specific analysis, which can be difficult to verify experimentally. Using two polarization-sensitive Johann-type crystal spectrometers at the National Institute of Standards and Technology (NIST) electron beam ion trap facility, we measured the linear polarization of well-known dielectronic recombination satellite transitions from Li-like Ar ions and two blended features from Be-like ions. The spectrometers observed the plasma at 90° relative to the electron beam propagation direction, and the crystal dispersion planes were oriented perpendicular relative to each other to allow for differing polarization sensitivities. Measurements were taken near the resonance energies of each line and compared with theoretical predictions based on relativistic magnetic sublevel atomic kinetics using the density-matrix theory. Most of the predictions are in excellent agreement with measured values.
Pulsating chromosphere of classical Cepheids. Calcium infrared triplet and Hα profile variationsHocdé, V.Nardetto, N.Borgniet, S.Lagadec, E.Kervella, P.Mérand, A.Evans, N.Gillet, D.Mathias, PhChiavassa, A.Gallenne, A.Breuval, L.Javanmardi, B.DOI: info:10.1051/0004-6361/202037795v. 641A74
Hocdé, V., Nardetto, N., Borgniet, S., Lagadec, E., Kervella, P., Mérand, A., Evans, N., Gillet, D., Mathias, Ph, Chiavassa, A., Gallenne, A., Breuval, L., and Javanmardi, B. 2020. "Pulsating chromosphere of classical Cepheids. Calcium infrared triplet and Hα profile variations." Astronomy and Astrophysics 641:A74. https://doi.org/10.1051/0004-6361/202037795
ID: 157683
Type: article
Authors: Hocdé, V.; Nardetto, N.; Borgniet, S.; Lagadec, E.; Kervella, P.; Mérand, A.; Evans, N.; Gillet, D.; Mathias, Ph; Chiavassa, A.; Gallenne, A.; Breuval, L.; Javanmardi, B.
Abstract: Context. It has recently been shown that the infrared (IR) emission of Cepheids, constant over the pulsation cycle, might be due to a pulsating shell of ionized gas with a radius of about 15% of that of the star radius, which could be attributed to the chromospheric activity of Cepheids.
Aims: The aim of this paper is to investigate the dynamical structure of the chromosphere of Cepheids along the pulsation cycle and to quantify its size.
Methods: We present Hα and calcium near-infrared triplet (Ca IR) profile variations using high-resolution spectroscopy with the UVES spectrograph of a sample of 24 Cepheids with a good period coverage from ≈3 to 60 days. After a qualitative analysis of the spectral line profiles, we quantified the Van Hoof effect (velocity gradient between the Hα and Ca IR) as a function of the period of the Cepheids. We then used the Schwarzschild mechanism (a line doubling due to a shock wave) to quantify the size of the chromosphere.
Results: We find a significant Van Hoof effect for Cepheids with a period larger than P = 10 days. In particular, Hα lines are delayed with a velocity gradient up to ∆v ≈ 30 km s-1 compared to Ca IR. By studying the shocks, we find that the size of the chromosphere of long-period Cepheids is of at least ≈50% of the stellar radius, which is consistent at first order with the size of the shell made of ionized gas previously found from the analysis of IR excess. Last, for most of the long-period Cepheids in the sample, we report a motionless absorption feature in the Hα line that we attribute to a circumstellar envelope that surrounds the chromosphere.
Conclusions: Analyzing the Ca IR lines of Cepheids is of importance to potentially unbias the period-luminosity relation from their IR excess, particularly in the context of forthcoming observations of radial velocity measurements from the Radial Velocity Spectrometer on board Gaia, which could be sensitive to their chromosphere.
Based on observations made with ESO telescopes at Paranal observatory under program IDs: 098.D-0379(A), 0100.D-0397(A) and 0101.D-0551(A).
Is Extended Hard X-Ray Emission Ubiquitous in Compton-thick AGN?Ma, JingzheElvis, MartinFabbiano, GiuseppinaBaloković, MislavMaksym, W. PeterJones, Mackenzie L.Risaliti, GuidoDOI: info:10.3847/1538-4357/abacbev. 900164
Ma, Jingzhe, Elvis, Martin, Fabbiano, Giuseppina, Baloković, Mislav, Maksym, W. Peter, Jones, Mackenzie L., and Risaliti, Guido. 2020. "Is Extended Hard X-Ray Emission Ubiquitous in Compton-thick AGN?." The Astrophysical Journal 900:164. https://doi.org/10.3847/1538-4357/abacbe
ID: 157684
Type: article
Authors: Ma, Jingzhe; Elvis, Martin; Fabbiano, Giuseppina; Baloković, Mislav; Maksym, W. Peter; Jones, Mackenzie L.; Risaliti, Guido
Abstract: The recent Chandra discovery of extended ∼kiloparsec-scale hard (>3 keV) X-ray emission in nearby Compton-thick (CT) active galactic nuclei (AGN) opens a new window to improving AGN torus modeling and investigating how the central supermassive black hole interacts with and impacts the host galaxy. Since there are only a handful of detections so far, we need to establish a statistical sample to determine the ubiquity of the extended hard X-ray emission in CT AGN and quantify the amount and extent of this component. In this paper, we present the spatial analysis results of a pilot Chandra imaging survey of seven nearby ( $0.006\lt z\lt 0.013$ ) CT AGN selected from the Swift-BAT spectroscopic AGN survey. We find that five out of the seven CT AGN show extended emission in the 3-7 keV band detected at >3σ above the Chandra point-spread function (PSF), with ∼12%-22% of the total emission in the extended components. ESO 137-G034 and NGC 3281 display biconical ionization structures with extended hard X-ray emission reaching kiloparsec scales (∼1.9 and 3.5 kpc in diameter). The other three show extended hard X-ray emission above the PSF out to at least ∼360 pc in radius. We find a trend that a minimum 3-7 keV count rate of 0.01 counts s-1 and total excess fraction >20% are required to detect a prominent extended hard X-ray component. Given that this extended hard X-ray component appears to be relatively common in this uniformly selected CT AGN sample, we further discuss the implications for torus modeling and AGN feedback.
Early Science from GOTHAM: Project Overview, Methods, and the Detection of Interstellar Propargyl Cyanide (HCCCH2CN) in TMC-1McGuire, Brett A.Burkhardt, Andrew M.Loomis, Ryan A.Shingledecker, Christopher N.Lee, Kin Long KelvinCharnley, Steven B.Cordiner, Martin A.Herbst, EricKalenskii, SergeiMomjian, EmmanuelWillis, Eric R.Xue, CiRemijan, Anthony J.McCarthy, Michael C.DOI: info:10.3847/2041-8213/aba632v. 900L10
McGuire, Brett A., Burkhardt, Andrew M., Loomis, Ryan A., Shingledecker, Christopher N., Lee, Kin Long Kelvin, Charnley, Steven B., Cordiner, Martin A., Herbst, Eric, Kalenskii, Sergei, Momjian, Emmanuel, Willis, Eric R., Xue, Ci, Remijan, Anthony J., and McCarthy, Michael C. 2020. "Early Science from GOTHAM: Project Overview, Methods, and the Detection of Interstellar Propargyl Cyanide (HCCCH2CN) in TMC-1." The Astrophysical Journal 900:L10. https://doi.org/10.3847/2041-8213/aba632
ID: 157685
Type: article
Authors: McGuire, Brett A.; Burkhardt, Andrew M.; Loomis, Ryan A.; Shingledecker, Christopher N.; Lee, Kin Long Kelvin; Charnley, Steven B.; Cordiner, Martin A.; Herbst, Eric; Kalenskii, Sergei; Momjian, Emmanuel; Willis, Eric R.; Xue, Ci; Remijan, Anthony J.; McCarthy, Michael C.
Abstract: We present an overview of the GBT Observations of TMC-1: Hunting Aromatic Molecules Large Program on the Green Bank Telescope. This and a related program were launched to explore the depth and breadth of aromatic chemistry in the interstellar medium at the earliest stages of star formation, following our earlier detection of benzonitrile (c-C6H5CN) in TMC-1. In this work, details of the observations, use of archival data, and data reduction strategies are provided. Using these observations, the interstellar detection of propargyl cyanide (HCCCH2CN) is described, as well as the accompanying laboratory spectroscopy. We discuss these results, and the survey project as a whole, in the context of investigating a previously unexplored reservoir of complex, gas-phase molecules in pre-stellar sources. A series of companion papers describe other new astronomical detections and analyses.
Zooming in on Individual Star Formation: Low- and High-Mass StarsRosen, Anna L.Offner, Stella S. R.Sadavoy, Sarah I.Bhandare, AsmitaVázquez-Semadeni, EnriqueGinsburg, AdamDOI: info:10.1007/s11214-020-00688-5v. 21662
Rosen, Anna L., Offner, Stella S. R., Sadavoy, Sarah I., Bhandare, Asmita, Vázquez-Semadeni, Enrique, and Ginsburg, Adam. 2020. "Zooming in on Individual Star Formation: Low- and High-Mass Stars." Space Science Reviews 216:62. https://doi.org/10.1007/s11214-020-00688-5
ID: 157686
Type: article
Authors: Rosen, Anna L.; Offner, Stella S. R.; Sadavoy, Sarah I.; Bhandare, Asmita; Vázquez-Semadeni, Enrique; Ginsburg, Adam
Abstract: Star formation is a multi-scale, multi-physics problem ranging from the size scale of molecular clouds (∼10 s pc) down to the size scales of dense prestellar cores (∼0.1 pc) that are the birth sites of stars. Several physical processes like turbulence, magnetic fields and stellar feedback, such as radiation pressure and outflows, are more or less important for different stellar masses and size scales. During the last decade a variety of technological and computing advances have transformed our understanding of star formation through the use of multi-wavelength observations, large scale observational surveys, and multi-physics multi-dimensional numerical simulations. Additionally, the use of synthetic observations of simulations have provided a useful tool to interpret observational data and evaluate the importance of various physical processes on different scales in star formation. Here, we review these recent advancements in both high- (M ≳8 M) and low-mass star formation.
Formation and Evolution of Disks Around Young Stellar ObjectsZhao, BoTomida, KengoHennebelle, PatrickTobin, John J.Maury, AnaëlleHirota, TomoyaSánchez-Monge, ÁlvaroKuiper, RolfRosen, Anna L.Bhandare, AsmitaPadovani, MarcoLee, Yueh-NingDOI: info:10.1007/s11214-020-00664-zv. 21643
Zhao, Bo, Tomida, Kengo, Hennebelle, Patrick, Tobin, John J., Maury, Anaëlle, Hirota, Tomoya, Sánchez-Monge, Álvaro, Kuiper, Rolf, Rosen, Anna L., Bhandare, Asmita, Padovani, Marco, and Lee, Yueh-Ning. 2020. "Formation and Evolution of Disks Around Young Stellar Objects." Space Science Reviews 216:43. https://doi.org/10.1007/s11214-020-00664-z
ID: 157687
Type: article
Authors: Zhao, Bo; Tomida, Kengo; Hennebelle, Patrick; Tobin, John J.; Maury, Anaëlle; Hirota, Tomoya; Sánchez-Monge, Álvaro; Kuiper, Rolf; Rosen, Anna L.; Bhandare, Asmita; Padovani, Marco; Lee, Yueh-Ning
Abstract: Recent observations have suggested that circumstellar disks may commonly form around young stellar objects. Although the formation of circumstellar disks can be a natural result of the conservation of angular momentum in the parent cloud, theoretical studies instead show disk formation to be difficult from dense molecular cores magnetized to a realistic level, owing to efficient magnetic braking that transports a large fraction of the angular momentum away from the circumstellar region. We review recent progress in the formation and early evolution of disks around young stellar objects of both low-mass and high-mass, with an emphasis on mechanisms that may bridge the gap between observation and theory, including non-ideal MHD effects and asymmetric perturbations in the collapsing core (e.g., magnetic field misalignment and turbulence). We also address the associated processes of outflow launching and the formation of multiple systems, and discuss possible implications in properties of protoplanetary disks.
Monitoring the Morphology of M87* in 2009-2017 with the Event Horizon TelescopeWielgus, MaciekAkiyama, KazunoriBlackburn, LindyChan, Chi-kwanDexter, JasonDoeleman, Sheperd S.Fish, Vincent L.Issaoun, SaraJohnson, Michael D.Krichbaum, Thomas P.Lu, Ru-SenPesce, Dominic W.Wong, George N.Bower, Geoffrey C.Broderick, Avery E.Chael, AndrewChatterjee, KoushikGammie, Charles F.Georgiev, BorisHada, KazuhiroLoinard, LaurentMarkoff, SeraMarrone, Daniel P.Plambeck, RichardWeintroub, JonathanDexter, MatthewMacMahon, David H. E.Wright, MelvynAlberdi, AntxonAlef, WalterAsada, KeiichiAzulay, RebeccaBaczko, Anne-KathrinBall, DavidBaloković, MislavBarausse, EnricoBarrett, JohnBintley, DanBoland, WilfredBouman, Katherine L.Bremer, MichaelBrinkerink, Christiaan D.Brissenden, RogerBritzen, SilkeBroguiere, DominiqueBronzwaer, ThomasByun, Do-YoungCarlstrom, John E.Chatterjee, ShamiChen, Ming-TangChen, YongjunCho, IljeChristian, PierreConway, John E.Cordes, James M.Crew, Geoffrey B.Cui, YuzhuDavelaar, JordyDe Laurentis, MariafeliciaeDeane, RogerDempsey, JessicaDesvignes, GregoryDzib, Sergio A.Eatough, Ralph P.Falcke, HeinoFomalont, EdFraga-Encinas, RaquelFriberg, PerFromm, Christian M.Galison, PeterGarcía, RobertoGentaz, OlivierGoddi, CiriacoGold, RomanGómez, José L.Gómez-Ruiz, Arturo I.Gu, MinfengGurwell, MarkHecht, Michael H.Hesper, RonaldHo, Luis C.Ho, PaulHonma, MarekiHuang, Chih-Wei L.Huang, LeiHughes, David H.Inoue, MakotoJames, David J.Jannuzi, Buell T.Janssen, MichaelJeter, BrittonJiang, WuJimenez-Rosales, AlejandraJorstad, SvetlanaJung, TaehyunKarami, MansourKaruppusamy, RameshKawashima, TomohisaKeating, Garrett K.Kettenis, MarkKim, Jae-YoungKim, JunhanKim, JongsooKino, MotokiKoay, Jun YiKoch, Patrick M.Koyama, ShokoKramer, MichaelKramer, CarstenKuo, Cheng-YuLauer, Tod R.Lee, Sang-SungLi, Yan-RongLi, ZhiyuanLindqvist, MichaelLico, RoccoLiu, KuoLiuzzo, ElisabettaLo, Wen-PingLobanov, Andrei P.Lonsdale, ColinMacDonald, Nicholas R.Mao, JirongMarchili, NicolaMarscher, Alan P.Martí-Vidal, IvánMatsushita, SatokiMatthews, Lynn D.Medeiros, LiaMenten, Karl M.Mizuno, YosukeMizuno, IzumiMoran, James M.Moriyama, KotaroMoscibrodzka, MonikaMüller, CorneliaMusoke, GibwaNagai, HiroshiNagar, Neil M.Nakamura, MasanoriNarayan, RameshNarayanan, GopalNatarajan, IniyanNathanail, AntoniosNeri, RobertoNi, ChunchongNoutsos, AristeidisOkino, HirokiOlivares, HéctorOrtiz-León, Gisela N.Oyama, TomoakiÖzel, FeryalPalumbo, Daniel C. M.Park, JonghoPatel, NimeshPen, Ue-LiPiétu, VincentPopStefanija, AleksandarPorth, OliverPrather, BenPreciado-López, Jorge A.Psaltis, DimitriosPu, Hung-YiRamakrishnan, VenkatesshRao, RamprasadRawlings, Mark G.Raymond, Alexander W.Rezzolla, LucianoRipperda, BartRoelofs, FreekRogers, AlanRos, EduardoRose, MelRoshanineshat, ArashRottmann, HelgeRoy, Alan L.Ruszczyk, ChetRyan, Benjamin R.Rygl, Kazi L. J.Sánchez, SalvadorSánchez-Arguelles, DavidSasada, MahitoSavolainen, TuomasSchloerb, F. PeterSchuster, Karl-FriedrichShao, LijingShen, ZhiqiangSmall, DesSohn, Bong WonSooHoo, JasonTazaki, FumieTiede, PaulTilanus, Remo P. J.Titus, MichaelToma, KenjiTorne, PabloTrent, TylerTraianou, EfthaliaTrippe, SaschaTsuda, Shuichirovan Bemmel, Ilsevan Langevelde, Huib Janvan Rossum, Daniel R.Wagner, JanWardle, JohnWard-Thompson, DerekWex, NorbertWharton, RobertWu, QingwenYoon, DoosooYoung, AndréYoung, KenYounsi, ZiriYuan, FengYuan, Ye-FeiZensus, J. AntonZhao, GuangyaoZhao, Shan-ShanZhu, ZiyanDOI: info:10.3847/1538-4357/abac0dv. 90167
Wielgus, Maciek, Akiyama, Kazunori, Blackburn, Lindy, Chan, Chi-kwan, Dexter, Jason, Doeleman, Sheperd S., Fish, Vincent L., Issaoun, Sara, Johnson, Michael D., Krichbaum, Thomas P., Lu, Ru-Sen, Pesce, Dominic W., Wong, George N., Bower, Geoffrey C., Broderick, Avery E., Chael, Andrew, Chatterjee, Koushik, Gammie, Charles F., Georgiev, Boris, Hada, Kazuhiro, Loinard, Laurent, Markoff, Sera, Marrone, Daniel P., Plambeck, Richard, Weintroub, Jonathan et al. 2020. "Monitoring the Morphology of M87* in 2009-2017 with the Event Horizon Telescope." The Astrophysical Journal 901:67. https://doi.org/10.3847/1538-4357/abac0d
ID: 157688
Type: article
Authors: Wielgus, Maciek; Akiyama, Kazunori; Blackburn, Lindy; Chan, Chi-kwan; Dexter, Jason; Doeleman, Sheperd S.; Fish, Vincent L.; Issaoun, Sara; Johnson, Michael D.; Krichbaum, Thomas P.; Lu, Ru-Sen; Pesce, Dominic W.; Wong, George N.; Bower, Geoffrey C.; Broderick, Avery E.; Chael, Andrew; Chatterjee, Koushik; Gammie, Charles F.; Georgiev, Boris; Hada, Kazuhiro; Loinard, Laurent; Markoff, Sera; Marrone, Daniel P.; Plambeck, Richard; Weintroub, Jonathan; Dexter, Matthew; MacMahon, David H. E.; Wright, Melvyn; Alberdi, Antxon; Alef, Walter; Asada, Keiichi; Azulay, Rebecca; Baczko, Anne-Kathrin; Ball, David; Baloković, Mislav; Barausse, Enrico; Barrett, John; Bintley, Dan; Boland, Wilfred; Bouman, Katherine L.; Bremer, Michael; Brinkerink, Christiaan D.; Brissenden, Roger; Britzen, Silke; Broguiere, Dominique; Bronzwaer, Thomas; Byun, Do-Young; Carlstrom, John E.; Chatterjee, Shami; Chen, Ming-Tang; Chen, Yongjun; Cho, Ilje; Christian, Pierre; Conway, John E.; Cordes, James M.; Crew, Geoffrey B.; Cui, Yuzhu; Davelaar, Jordy; De Laurentis, Mariafeliciae; Deane, Roger; Dempsey, Jessica; Desvignes, Gregory; Dzib, Sergio A.; Eatough, Ralph P.; Falcke, Heino; Fomalont, Ed; Fraga-Encinas, Raquel; Friberg, Per; Fromm, Christian M.; Galison, Peter; García, Roberto; Gentaz, Olivier; Goddi, Ciriaco; Gold, Roman; Gómez, José L.; Gómez-Ruiz, Arturo I.; Gu, Minfeng; Gurwell, Mark; Hecht, Michael H.; Hesper, Ronald; Ho, Luis C.; Ho, Paul; Honma, Mareki; Huang, Chih-Wei L.; Huang, Lei; Hughes, David H.; Inoue, Makoto; James, David J.; Jannuzi, Buell T.; Janssen, Michael; Jeter, Britton; Jiang, Wu; Jimenez-Rosales, Alejandra; Jorstad, Svetlana; Jung, Taehyun; Karami, Mansour; Karuppusamy, Ramesh; Kawashima, Tomohisa; Keating, Garrett K.; Kettenis, Mark; Kim, Jae-Young; Kim, Junhan; Kim, Jongsoo; Kino, Motoki; Koay, Jun Yi; Koch, Patrick M.; Koyama, Shoko; Kramer, Michael; Kramer, Carsten; Kuo, Cheng-Yu; Lauer, Tod R.; Lee, Sang-Sung; Li, Yan-Rong; Li, Zhiyuan; Lindqvist, Michael; Lico, Rocco; Liu, Kuo; Liuzzo, Elisabetta; Lo, Wen-Ping; Lobanov, Andrei P.; Lonsdale, Colin; MacDonald, Nicholas R.; Mao, Jirong; Marchili, Nicola; Marscher, Alan P.; Martí-Vidal, Iván; Matsushita, Satoki; Matthews, Lynn D.; Medeiros, Lia; Menten, Karl M.; Mizuno, Yosuke; Mizuno, Izumi; Moran, James M.; Moriyama, Kotaro; Moscibrodzka, Monika; Müller, Cornelia; Musoke, Gibwa; Nagai, Hiroshi; Nagar, Neil M.; Nakamura, Masanori; Narayan, Ramesh; Narayanan, Gopal; Natarajan, Iniyan; Nathanail, Antonios; Neri, Roberto; Ni, Chunchong; Noutsos, Aristeidis; Okino, Hiroki; Olivares, Héctor; Ortiz-León, Gisela N.; Oyama, Tomoaki; Özel, Feryal; Palumbo, Daniel C. M.; Park, Jongho; Patel, Nimesh; Pen, Ue-Li; Piétu, Vincent; PopStefanija, Aleksandar; Porth, Oliver; Prather, Ben; Preciado-López, Jorge A.; Psaltis, Dimitrios; Pu, Hung-Yi; Ramakrishnan, Venkatessh; Rao, Ramprasad; Rawlings, Mark G.; Raymond, Alexander W.; Rezzolla, Luciano; Ripperda, Bart; Roelofs, Freek; Rogers, Alan; Ros, Eduardo; Rose, Mel; Roshanineshat, Arash; Rottmann, Helge; Roy, Alan L.; Ruszczyk, Chet; Ryan, Benjamin R.; Rygl, Kazi L. J.; Sánchez, Salvador; Sánchez-Arguelles, David; Sasada, Mahito; Savolainen, Tuomas; Schloerb, F. Peter; Schuster, Karl-Friedrich; Shao, Lijing; Shen, Zhiqiang; Small, Des; Sohn, Bong Won; SooHoo, Jason; Tazaki, Fumie; Tiede, Paul; Tilanus, Remo P. J.; Titus, Michael; Toma, Kenji; Torne, Pablo; Trent, Tyler; Traianou, Efthalia; Trippe, Sascha; Tsuda, Shuichiro; van Bemmel, Ilse; van Langevelde, Huib Jan; van Rossum, Daniel R.; Wagner, Jan; Wardle, John; Ward-Thompson, Derek; Wex, Norbert; Wharton, Robert; Wu, Qingwen; Yoon, Doosoo; Young, André; Young, Ken; Younsi, Ziri; Yuan, Feng; Yuan, Ye-Fei; Zensus, J. Anton; Zhao, Guangyao; Zhao, Shan-Shan; Zhu, Ziyan
Abstract: The Event Horizon Telescope (EHT) has recently delivered the first resolved images of M87*, the supermassive black hole in the center of the M87 galaxy. These images were produced using 230 GHz observations performed in 2017 April. Additional observations are required to investigate the persistence of the primary image feature-a ring with azimuthal brightness asymmetry-and to quantify the image variability on event horizon scales. To address this need, we analyze M87* data collected with prototype EHT arrays in 2009, 2011, 2012, and 2013. While these observations do not contain enough information to produce images, they are sufficient to constrain simple geometric models. We develop a modeling approach based on the framework utilized for the 2017 EHT data analysis and validate our procedures using synthetic data. Applying the same approach to the observational data sets, we find the M87* morphology in 2009-2017 to be consistent with a persistent asymmetric ring of ∼40 μas diameter. The position angle of the peak intensity varies in time. In particular, we find a significant difference between the position angle measured in 2013 and 2017. These variations are in broad agreement with predictions of a subset of general relativistic magnetohydrodynamic simulations. We show that quantifying the variability across multiple observational epochs has the potential to constrain the physical properties of the source, such as the accretion state or the black hole spin.
Molecular Gas Properties on Cloud Scales across the Local Star-forming Galaxy PopulationSun, JiayiLeroy, Adam K.Schinnerer, EvaHughes, AnnieRosolowsky, ErikQuerejeta, MiguelSchruba, AndreasLiu, DaizhongSaito, ToshikiHerrera, Cinthya N.Faesi, ChristopherUsero, AntonioPety, JérômeKruijssen, J. M. DiederikOstriker, Eve C.Bigiel, FrankBlanc, Guillermo A.Bolatto, Alberto D.Boquien, MédéricChevance, MélanieDale, Daniel A.Deger, SinanEmsellem, EricGlover, Simon C. O.Grasha, KathrynGroves, BrentHenshaw, JonathanJimenez-Donaire, Maria J.Kim, Jenny J.Klessen, Ralf S.Kreckel, KathrynLee, Janice C.Meidt, SharonSandstrom, KarinSardone, Amy E.Utomo, DyasWilliams, Thomas G.DOI: info:10.3847/2041-8213/abb3bev. 901L8
Sun, Jiayi, Leroy, Adam K., Schinnerer, Eva, Hughes, Annie, Rosolowsky, Erik, Querejeta, Miguel, Schruba, Andreas, Liu, Daizhong, Saito, Toshiki, Herrera, Cinthya N., Faesi, Christopher, Usero, Antonio, Pety, Jérôme, Kruijssen, J. M. Diederik, Ostriker, Eve C., Bigiel, Frank, Blanc, Guillermo A., Bolatto, Alberto D., Boquien, Médéric, Chevance, Mélanie, Dale, Daniel A., Deger, Sinan, Emsellem, Eric, Glover, Simon C. O., Grasha, Kathryn et al. 2020. "Molecular Gas Properties on Cloud Scales across the Local Star-forming Galaxy Population." The Astrophysical Journal 901:L8. https://doi.org/10.3847/2041-8213/abb3be
ID: 157689
Type: article
Authors: Sun, Jiayi; Leroy, Adam K.; Schinnerer, Eva; Hughes, Annie; Rosolowsky, Erik; Querejeta, Miguel; Schruba, Andreas; Liu, Daizhong; Saito, Toshiki; Herrera, Cinthya N.; Faesi, Christopher; Usero, Antonio; Pety, Jérôme; Kruijssen, J. M. Diederik; Ostriker, Eve C.; Bigiel, Frank; Blanc, Guillermo A.; Bolatto, Alberto D.; Boquien, Médéric; Chevance, Mélanie; Dale, Daniel A.; Deger, Sinan; Emsellem, Eric; Glover, Simon C. O.; Grasha, Kathryn; Groves, Brent; Henshaw, Jonathan; Jimenez-Donaire, Maria J.; Kim, Jenny J.; Klessen, Ralf S.; Kreckel, Kathryn; Lee, Janice C.; Meidt, Sharon; Sandstrom, Karin; Sardone, Amy E.; Utomo, Dyas; Williams, Thomas G.
Abstract: Using the PHANGS-ALMA CO(2-1) survey, we characterize molecular gas properties on ∼100 pc scales across 102,778 independent sightlines in 70 nearby galaxies. This yields the best synthetic view of molecular gas properties on cloud scales across the local star-forming galaxy population obtained to date. Consistent with previous studies, we observe a wide range of molecular gas surface densities (3.4 dex), velocity dispersions (1.7 dex), and turbulent pressures (6.5 dex) across the galaxies in our sample. Under simplifying assumptions about subresolution gas structure, the inferred virial parameters suggest that the kinetic energy of the molecular gas typically exceeds its self-gravitational binding energy at ∼100 pc scales by a modest factor (1.3 on average). We find that the cloud-scale surface density, velocity dispersion, and turbulent pressure (1) increase toward the inner parts of galaxies, (2) are exceptionally high in the centers of barred galaxies (where the gas also appears less gravitationally bound), and (3) are moderately higher in spiral arms than in inter-arm regions. The galaxy-wide averages of these gas properties also correlate with the integrated stellar mass, star formation rate, and offset from the star-forming main sequence of the host galaxies. These correlations persist even when we exclude regions with extraordinary gas properties in galaxy centers, which contribute significantly to the inter-galaxy variations. Our results provide key empirical constraints on the physical link between molecular cloud populations and their galactic environment.
The Sloan Digital Sky Survey Quasar Catalog: Sixteenth Data ReleaseLyke, Brad W.Higley, Alexandra N.McLane, J. N.Schurhammer, Danielle P.Myers, Adam D.Ross, Ashley J.Dawson, KyleChabanier, SolèneMartini, PaulBusca, Nicolás G.Mas des Bourboux, Hélion duSalvato, MaraStreblyanska, AlinaZarrouk, PaulineBurtin, EtienneAnderson, Scott F.Bautista, JulianBizyaev, DmitryBrandt, W. N.Brinkmann, JonathanBrownstein, Joel R.Comparat, JohanGreen, Paulde la Macorra, AxelMuñoz Gutiérrez, AndreaHou, JiaminNewman, Jeffrey A.Palanque-Delabrouille, NathaliePâris, IsabellePercival, Will J.Petitjean, PatrickRich, JamesRossi, GrazianoSchneider, Donald P.Smith, AlexanderVivek, M.Weaver, Benjamin AlanDOI: info:10.3847/1538-4365/aba623v. 2508
Lyke, Brad W., Higley, Alexandra N., McLane, J. N., Schurhammer, Danielle P., Myers, Adam D., Ross, Ashley J., Dawson, Kyle, Chabanier, Solène, Martini, Paul, Busca, Nicolás G., Mas des Bourboux, Hélion du, Salvato, Mara, Streblyanska, Alina, Zarrouk, Pauline, Burtin, Etienne, Anderson, Scott F., Bautista, Julian, Bizyaev, Dmitry, Brandt, W. N., Brinkmann, Jonathan, Brownstein, Joel R., Comparat, Johan, Green, Paul, de la Macorra, Axel, Muñoz Gutiérrez, Andrea et al. 2020. "The Sloan Digital Sky Survey Quasar Catalog: Sixteenth Data Release." The Astrophysical Journal Supplement Series 250:8. https://doi.org/10.3847/1538-4365/aba623
ID: 157690
Type: article
Authors: Lyke, Brad W.; Higley, Alexandra N.; McLane, J. N.; Schurhammer, Danielle P.; Myers, Adam D.; Ross, Ashley J.; Dawson, Kyle; Chabanier, Solène; Martini, Paul; Busca, Nicolás G.; Mas des Bourboux, Hélion du; Salvato, Mara; Streblyanska, Alina; Zarrouk, Pauline; Burtin, Etienne; Anderson, Scott F.; Bautista, Julian; Bizyaev, Dmitry; Brandt, W. N.; Brinkmann, Jonathan; Brownstein, Joel R.; Comparat, Johan; Green, Paul; de la Macorra, Axel; Muñoz Gutiérrez, Andrea; Hou, Jiamin; Newman, Jeffrey A.; Palanque-Delabrouille, Nathalie; Pâris, Isabelle; Percival, Will J.; Petitjean, Patrick; Rich, James; Rossi, Graziano; Schneider, Donald P.; Smith, Alexander; Vivek, M.; Weaver, Benjamin Alan
Abstract: We present the final Sloan Digital Sky Survey IV (SDSS-IV) quasar catalog from Data Release 16 of the extended Baryon Oscillation Spectroscopic Survey (eBOSS). This catalog comprises the largest selection of spectroscopically confirmed quasars to date. The full catalog includes two subcatalogs (the current versions are DR16Q_v4 and DR16Q_Superset_v3 at https://data.sdss.org/sas/dr16/eboss/qso/DR16Q/): a "superset" of all SDSS-IV/eBOSS objects targeted as quasars containing 1,440,615 observations and a quasar-only catalog containing 750,414 quasars, including 225,082 new quasars appearing in an SDSS data release for the first time, as well as known quasars from SDSS-I/II/III. We present automated identification and redshift information for these quasars alongside data from visual inspections for 320,161 spectra. The quasar-only catalog is estimated to be 99.8% complete with 0.3%-1.3% contamination. Automated and visual inspection redshifts are supplemented by redshifts derived via principal component analysis and emission lines. We include emission-line redshifts for Hα, Hβ, Mg II, C III], C IV, and Lyα. Identification and key characteristics generated by automated algorithms are presented for 99,856 broad absorption-line quasars and 35,686 damped Lyman alpha quasars. In addition to SDSS photometric data, we also present multiwavelength data for quasars from the Galaxy Evolution Explorer, UKIDSS, the Wide-field Infrared Survey Explorer, FIRST, ROSAT/2RXS, XMM-Newton, and Gaia. Calibrated digital optical spectra for these quasars can be obtained from the SDSS Science Archive Server.
The Sloan Digital Sky Survey Reverberation Mapping Project: Mg II Lag Results from Four Years of MonitoringHomayouni, Y.Trump, Jonathan R.Grier, C. J.Horne, KeithShen, YueBrandt, W. N.Dawson, Kyle S.Alvarez, Gloria FonsecaGreen, Paul J.Hall, P. B.Hernández Santisteban, Juan V.Ho, Luis C.Kinemuchi, KarenKochanek, C. S.Li, Jennifer I. -HsiuPeterson, B. M.Schneider, D. P.Starkey, D. A.Bizyaev, DmitryPan, KaikeOravetz, DanielSimmons, AudreyDOI: info:10.3847/1538-4357/ababa9v. 90155
Homayouni, Y., Trump, Jonathan R., Grier, C. J., Horne, Keith, Shen, Yue, Brandt, W. N., Dawson, Kyle S., Alvarez, Gloria Fonseca, Green, Paul J., Hall, P. B., Hernández Santisteban, Juan V., Ho, Luis C., Kinemuchi, Karen, Kochanek, C. S., Li, Jennifer I. -Hsiu, Peterson, B. M., Schneider, D. P., Starkey, D. A., Bizyaev, Dmitry, Pan, Kaike, Oravetz, Daniel, and Simmons, Audrey. 2020. "The Sloan Digital Sky Survey Reverberation Mapping Project: Mg II Lag Results from Four Years of Monitoring." The Astrophysical Journal 901:55. https://doi.org/10.3847/1538-4357/ababa9
ID: 157691
Type: article
Authors: Homayouni, Y.; Trump, Jonathan R.; Grier, C. J.; Horne, Keith; Shen, Yue; Brandt, W. N.; Dawson, Kyle S.; Alvarez, Gloria Fonseca; Green, Paul J.; Hall, P. B.; Hernández Santisteban, Juan V.; Ho, Luis C.; Kinemuchi, Karen; Kochanek, C. S.; Li, Jennifer I. -Hsiu; Peterson, B. M.; Schneider, D. P.; Starkey, D. A.; Bizyaev, Dmitry; Pan, Kaike; Oravetz, Daniel; Simmons, Audrey
Abstract: We present reverberation mapping results for the Mg II λ2800 Å broad emission line in a sample of 193 quasars at $0.35\lt z\lt 1.7$ with photometric and spectroscopic monitoring observations from the Sloan Digital Sky Survey Reverberation Mapping project during 2014-2017. We find significant time lags between the Mg II and continuum lightcurves for 57 quasars, and define a "gold sample" of 24 quasars with the most reliable lag measurements. We estimate false-positive rates for each lag that range from 1% to 24%, with an average false-positive rate of 11% for the full sample and 8% for the gold sample. There are an additional ∼40 quasars with marginal Mg II lag detections, which may yield reliable lags after additional years of monitoring. The Mg II lags follow a radius-luminosity relation with a best-fit slope that is consistent with $\alpha =0.5$ , but with an intrinsic scatter of 0.36 dex that is significantly larger than found for the Hβ radius-luminosity relation. For targets with SDSS-RM lag measurements of other emission lines, we find that our Mg II lags are similar to the Hβ lags and ∼2-3 times larger than the C IV lags. This work significantly increases the number of Mg II broad-line lags and provides additional reverberation-mapped black hole masses, filling the redshift gap at the peak of supermassive black hole growth between the Hβ and C IV emission lines in optical spectroscopy.
Classifying Single Stars and Spectroscopic Binaries Using Optical Stellar TemplatesRoulston, Benjamin R.Green, Paul J.Kesseli, Aurora Y.DOI: info:10.3847/1538-4365/aba1e7v. 24934
Roulston, Benjamin R., Green, Paul J., and Kesseli, Aurora Y. 2020. "Classifying Single Stars and Spectroscopic Binaries Using Optical Stellar Templates." The Astrophysical Journal Supplement Series 249:34. https://doi.org/10.3847/1538-4365/aba1e7
ID: 157692
Type: article
Authors: Roulston, Benjamin R.; Green, Paul J.; Kesseli, Aurora Y.
Abstract: Stellar spectral classification is a fundamental tool of modern astronomy, providing insight into physical characteristics such as effective temperature, surface gravity, and metallicity. Accurate and fast spectral typing is an integral need for large all-sky spectroscopic surveys like the Sloan Digital Sky Survey (SDSS) and the Large Sky Area Multi-Object Fiber Spectroscopic Telescope. Here, we present the next version of PyHammer, a stellar spectral classification software that uses optical spectral templates and spectral line index measurements. PyHammer v2.0 extends the classification power to include dwarf carbon stars, DA white dwarf stars, and also double-lined spectroscopic binaries (SB2). This release also includes a new empirical library of luminosity-normalized spectra that can be used to flux calibrate observed spectra or to create synthetic SB2 spectra. We have generated physically reasonable SB2 combinations as templates, adding the ability to spectrally type SB2s to PyHammer. We test classification success rates on SB2 spectra, generated from the SDSS, across a wide range of spectral types and signal-to-noise ratios. Within the defined range of pairings described, more than 95% of SB2s are correctly classified.
Constraints on the Physical Properties of GW190814 through Simulations Based on DECam Follow-up Observations by the Dark Energy SurveyMorgan, R.Soares-Santos, M.Annis, J.Herner, K.Garcia, A.Palmese, A.Drlica-Wagner, A.Kessler, R.García-Bellido, J.Bachmann, T. G.Sherman, N.Allam, S.Bechtol, K.Bom, C. R.Brout, D.Butler, R. E.Butner, M.Cartier, R.Chen, H.Conselice, C.Cook, E.Davis, T. M.Doctor, Z.Farr, B.Figueiredo, A. L.Finley, D. A.Foley, R. J.Galarza, J. Y.Gill, M. S. S.Gruendl, R. A.Holz, D. E.Kuropatkin, N.Lidman, C.Lin, H.Malik, U.Mann, A. W.Marriner, J.Marshall, J. L.Martínez-Vázquez, C. E.Meza, N.Neilsen, E.Nicolaou, C.Olivares E., F.Paz-Chinchón, F.Points, S.Quirola-Vásquez, J.Rodriguez, O.Sako, M.Scolnic, D.Smith, M.Sobreira, F.Tucker, D. L.Vivas, A. K.Wiesner, M.Wood, M. L.Yanny, B.Zenteno, A.Abbott, T. M. C.Aguena, M.Avila, S.Bertin, E.Bhargava, S.Brooks, D.Burke, D. L.Carnero Rosell, A.Carrasco Kind, M.Carretero, J.da Costa, L. N.Costanzi, M.De Vicente, J.Desai, S.Diehl, H. T.Doel, P.Eifler, T. F.Everett, S.Flaugher, B.Frieman, J.Gaztanaga, E.Gerdes, D. W.Gruen, D.Gschwend, J.Gutierrez, G.Hartley, W. G.Hinton, S. R.Hollowood, D. L.Honscheid, K.James, David J.Kuehn, K.Lahav, O.Lima, M.Maia, M. A. G.March, M.Miquel, R.Ogando, R. L. C.Plazas, A. A.Roodman, A.Sanchez, E.Scarpine, V.Schubnell, M.Serrano, S.Sevilla-Noarbe, I.Suchyta, E.Tarle, G.DOI: info:10.3847/1538-4357/abafaav. 90183
Morgan, R., Soares-Santos, M., Annis, J., Herner, K., Garcia, A., Palmese, A., Drlica-Wagner, A., Kessler, R., García-Bellido, J., Bachmann, T. G., Sherman, N., Allam, S., Bechtol, K., Bom, C. R., Brout, D., Butler, R. E., Butner, M., Cartier, R., Chen, H., Conselice, C., Cook, E., Davis, T. M., Doctor, Z., Farr, B., Figueiredo, A. L. et al. 2020. "Constraints on the Physical Properties of GW190814 through Simulations Based on DECam Follow-up Observations by the Dark Energy Survey." The Astrophysical Journal 901:83. https://doi.org/10.3847/1538-4357/abafaa
ID: 157693
Type: article
Authors: Morgan, R.; Soares-Santos, M.; Annis, J.; Herner, K.; Garcia, A.; Palmese, A.; Drlica-Wagner, A.; Kessler, R.; García-Bellido, J.; Bachmann, T. G.; Sherman, N.; Allam, S.; Bechtol, K.; Bom, C. R.; Brout, D.; Butler, R. E.; Butner, M.; Cartier, R.; Chen, H.; Conselice, C.; Cook, E.; Davis, T. M.; Doctor, Z.; Farr, B.; Figueiredo, A. L.; Finley, D. A.; Foley, R. J.; Galarza, J. Y.; Gill, M. S. S.; Gruendl, R. A.; Holz, D. E.; Kuropatkin, N.; Lidman, C.; Lin, H.; Malik, U.; Mann, A. W.; Marriner, J.; Marshall, J. L.; Martínez-Vázquez, C. E.; Meza, N.; Neilsen, E.; Nicolaou, C.; Olivares E., F.; Paz-Chinchón, F.; Points, S.; Quirola-Vásquez, J.; Rodriguez, O.; Sako, M.; Scolnic, D.; Smith, M.; Sobreira, F.; Tucker, D. L.; Vivas, A. K.; Wiesner, M.; Wood, M. L.; Yanny, B.; Zenteno, A.; Abbott, T. M. C.; Aguena, M.; Avila, S.; Bertin, E.; Bhargava, S.; Brooks, D.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; da Costa, L. N.; Costanzi, M.; De Vicente, J.; Desai, S.; Diehl, H. T.; Doel, P.; Eifler, T. F.; Everett, S.; Flaugher, B.; Frieman, J.; Gaztanaga, E.; Gerdes, D. W.; Gruen, D.; Gschwend, J.; Gutierrez, G.; Hartley, W. G.; Hinton, S. R.; Hollowood, D. L.; Honscheid, K.; James, David J.; Kuehn, K.; Lahav, O.; Lima, M.; Maia, M. A. G.; March, M.; Miquel, R.; Ogando, R. L. C.; Plazas, A. A.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Serrano, S.; Sevilla-Noarbe, I.; Suchyta, E.; Tarle, G.
Abstract: On 2019 August 14, the LIGO and Virgo Collaborations detected gravitational waves from a black hole and a 2.6 solar mass compact object, possibly the first neutron star-black hole merger. In search of an optical counterpart, the Dark Energy Survey (DES) obtained deep imaging of the entire 90% confidence level localization area with Blanco/DECam 0, 1, 2, 3, 6, and 16 nights after the merger. Objects with varying brightness were detected by the DES Pipeline, and we systematically reduced the candidate counterparts through catalog matching, light-curve properties, host-galaxy photometric redshifts, Southern Astrophysical Research spectroscopic follow-up observations, and machine-learning-based photometric classification. All candidates were rejected as counterparts to the merger. To quantify the sensitivity of our search, we applied our selection criteria to full light-curve simulations of supernovae and kilonovae as they would appear in the DECam observations. Because the source class of the merger was uncertain, we utilized an agnostic, three-component kilonova model based on tidally disrupted neutron star (NS) ejecta properties to quantify our detection efficiency of a counterpart if the merger included an NS. We find that, if a kilonova occurred during this merger, configurations where the ejected matter is greater than 0.07 solar masses, has lanthanide abundance less than 10-8.56, and has a velocity between 0.18c and 0.21c are disfavored at the 2σ level. Furthermore, we estimate that our background reduction methods are capable of associating gravitational wave signals with a detected electromagnetic counterpart at the 4σ level in 95% of future follow-up observations.
A Search for Light Hydrides in the Envelopes of Evolved StarsSiebert, Mark A.Simon, IgnacioShingledecker, Christopher N.Carroll, P. BrandonBurkhardt, Andrew M.Booth, Shawn ThomasRemijan, Anthony J.McGuire, Brett A.Aladro, RebecaDuran, Carlos A.DOI: info:10.3847/1538-4357/abac0ev. 90122
Siebert, Mark A., Simon, Ignacio, Shingledecker, Christopher N., Carroll, P. Brandon, Burkhardt, Andrew M., Booth, Shawn Thomas, Remijan, Anthony J., McGuire, Brett A., Aladro, Rebeca, and Duran, Carlos A. 2020. "A Search for Light Hydrides in the Envelopes of Evolved Stars." The Astrophysical Journal 901:22. https://doi.org/10.3847/1538-4357/abac0e
ID: 157694
Type: article
Authors: Siebert, Mark A.; Simon, Ignacio; Shingledecker, Christopher N.; Carroll, P. Brandon; Burkhardt, Andrew M.; Booth, Shawn Thomas; Remijan, Anthony J.; McGuire, Brett A.; Aladro, Rebeca; Duran, Carlos A.
Abstract: We report a search for the diatomic hydrides SiH, PH, and FeH along the line of sight toward the chemically rich circumstellar envelopes of IRC+10216 and VY Canis Majoris. These molecules are thought to form in high-temperature regions near the photospheres of those stars, and may then further react via gas-phase and dust-grain interactions leading to more complex species, but have yet to be constrained by observation. We used the German Receiver for Astronomy at Terahertz Frequencies spectrometer on the Stratospheric Observatory for Infrared Astronomy to search for rotational emission lines of these molecules in four spectral windows ranging from 600 to 1500 GHz. Although none of the targeted species was detected in our search, we report their upper limit abundances in each source and discuss how they influence the current understanding of hydride chemistry in dense circumstellar media. We attribute the nondetections of these hydrides to their compact source sizes, high barriers of formation, and proclivity to react with other molecules in the winds.
Chandra Observations of Candidate Subparsec Binary Supermassive Black HolesSaade, M. LynneStern, DanielBrightman, MurrayHaiman, ZoltánDjorgovski, S. G.D'Orazio, DanielFord, K. E. S.Graham, Matthew J.Jun, Hyunsung D.Kraft, Ralph P.McKernan, BarryVikhlinin, AlexeyWalton, Dominic J.DOI: info:10.3847/1538-4357/abad31v. 900148
Saade, M. Lynne, Stern, Daniel, Brightman, Murray, Haiman, Zoltán, Djorgovski, S. G., D'Orazio, Daniel, Ford, K. E. S., Graham, Matthew J., Jun, Hyunsung D., Kraft, Ralph P., McKernan, Barry, Vikhlinin, Alexey, and Walton, Dominic J. 2020. "Chandra Observations of Candidate Subparsec Binary Supermassive Black Holes." The Astrophysical Journal 900:148. https://doi.org/10.3847/1538-4357/abad31
ID: 157695
Type: article
Authors: Saade, M. Lynne; Stern, Daniel; Brightman, Murray; Haiman, Zoltán; Djorgovski, S. G.; D'Orazio, Daniel; Ford, K. E. S.; Graham, Matthew J.; Jun, Hyunsung D.; Kraft, Ralph P.; McKernan, Barry; Vikhlinin, Alexey; Walton, Dominic J.
Abstract: We present analysis of Chandra X-ray observations of seven quasars that were identified as candidate subparsec binary supermassive black hole (SMBH) systems in the Catalina Real-Time Transient Survey based on the apparent periodicity in their optical light curves. Simulations predict that close-separation accreting SMBH binaries will have different X-ray spectra than single accreting SMBHs, including harder or softer X-ray spectra, ripple-like profiles in the Fe K-α line, and distinct peaks in the spectrum due to the separation of the accretion disk into a circumbinary disk and mini disks around each SMBH. We obtained Chandra observations to test these models and assess whether these quasars could contain binary SMBHs. We instead find that the quasar spectra are all well fit by simple absorbed power-law models, with the rest-frame 2-10 keV photon indices, Γ, and the X-ray-to-optical power slopes, αOX, indistinguishable from those of the larger quasar population. This may indicate that these seven quasars are not truly subparsec binary SMBH systems, or it may simply reflect that our sample size was too small to robustly detect any differences. Alternatively, the X-ray spectral changes might only be evident at energies higher than probed by Chandra. Given the available models and current data, no firm conclusions are drawn. These observations will help motivate and direct further work on theoretical models of binary SMBH systems, such as modeling systems with thinner accretion disks and larger binary separations.
A Statistical Standard Siren Measurement of the Hubble Constant from the LIGO/Virgo Gravitational Wave Compact Object Merger GW190814 and Dark Energy Survey GalaxiesPalmese, A.deVicente, J.Pereira, M. E. S.Annis, J.Hartley, W.Herner, K.Soares-Santos, M.Crocce, M.Huterer, D.Magaña Hernandez, I.Garcia, A.Garcia-Bellido, J.Gschwend, J.Holz, D. E.Kessler, R.Lahav, O.Morgan, R.Nicolaou, C.Conselice, C.Foley, R. J.Gill, M. S. S.Abbott, T. M. C.Aguena, M.Allam, S.Avila, S.Bechtol, K.Bertin, E.Bhargava, S.Brooks, D.Buckley-Geer, E.Burke, D. L.Carrasco Kind, M.Carretero, J.Castander, F. J.Chang, C.Costanzi, M.da Costa, L. N.Davis, T. M.Desai, S.Diehl, H. T.Doel, P.Drlica-Wagner, A.Estrada, J.Everett, S.Evrard, A. E.Fernandez, E.Finley, D. A.Flaugher, B.Fosalba, P.Frieman, J.Gaztanaga, E.Gerdes, D. W.Gruen, D.Gruendl, R. A.Gutierrez, G.Hinton, S. R.Hollowood, D. L.Honscheid, K.James, David J.Kent, S.Krause, E.Kuehn, K.Lin, H.Maia, M. A. G.March, M.Marshall, J. L.Melchior, P.Menanteau, F.Miquel, R.Ogando, R. L. C.Paz-Chinchón, F.Plazas, A. A.Roodman, A.Sako, M.Sanchez, E.Scarpine, V.Schubnell, M.Serrano, S.Sevilla-Noarbe, I.Smith, J. AllynSmith, M.Suchyta, E.Tarle, G.Troxel, M. A.Tucker, D. L.Walker, A. R.Wester, W.Wilkinson, R. D.Zuntz, J.DES CollaborationDOI: info:10.3847/2041-8213/abaeffv. 900L33
Palmese, A., deVicente, J., Pereira, M. E. S., Annis, J., Hartley, W., Herner, K., Soares-Santos, M., Crocce, M., Huterer, D., Magaña Hernandez, I., Garcia, A., Garcia-Bellido, J., Gschwend, J., Holz, D. E., Kessler, R., Lahav, O., Morgan, R., Nicolaou, C., Conselice, C., Foley, R. J., Gill, M. S. S., Abbott, T. M. C., Aguena, M., Allam, S., Avila, S. et al. 2020. "A Statistical Standard Siren Measurement of the Hubble Constant from the LIGO/Virgo Gravitational Wave Compact Object Merger GW190814 and Dark Energy Survey Galaxies." The Astrophysical Journal 900:L33. https://doi.org/10.3847/2041-8213/abaeff
ID: 157696
Type: article
Authors: Palmese, A.; deVicente, J.; Pereira, M. E. S.; Annis, J.; Hartley, W.; Herner, K.; Soares-Santos, M.; Crocce, M.; Huterer, D.; Magaña Hernandez, I.; Garcia, A.; Garcia-Bellido, J.; Gschwend, J.; Holz, D. E.; Kessler, R.; Lahav, O.; Morgan, R.; Nicolaou, C.; Conselice, C.; Foley, R. J.; Gill, M. S. S.; Abbott, T. M. C.; Aguena, M.; Allam, S.; Avila, S.; Bechtol, K.; Bertin, E.; Bhargava, S.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Carrasco Kind, M.; Carretero, J.; Castander, F. J.; Chang, C.; Costanzi, M.; da Costa, L. N.; Davis, T. M.; Desai, S.; Diehl, H. T.; Doel, P.; Drlica-Wagner, A.; Estrada, J.; Everett, S.; Evrard, A. E.; Fernandez, E.; Finley, D. A.; Flaugher, B.; Fosalba, P.; Frieman, J.; Gaztanaga, E.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Gutierrez, G.; Hinton, S. R.; Hollowood, D. L.; Honscheid, K.; James, David J.; Kent, S.; Krause, E.; Kuehn, K.; Lin, H.; Maia, M. A. G.; March, M.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Miquel, R.; Ogando, R. L. C.; Paz-Chinchón, F.; Plazas, A. A.; Roodman, A.; Sako, M.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Serrano, S.; Sevilla-Noarbe, I.; Smith, J. Allyn; Smith, M.; Suchyta, E.; Tarle, G.; Troxel, M. A.; Tucker, D. L.; Walker, A. R.; Wester, W.; Wilkinson, R. D.; Zuntz, J.; DES Collaboration
Abstract: We present a measurement of the Hubble constant H0 using the gravitational wave (GW) event GW190814, which resulted from the coalescence of a 23 M black hole with a 2.6 M compact object, as a standard siren. No compelling electromagnetic counterpart has been identified for this event; thus our analysis accounts for thousands of potential host galaxies within a statistical framework. The redshift information is obtained from the photometric redshift (photo-z) catalog from the Dark Energy Survey. The luminosity distance is provided by the LIGO/Virgo gravitational wave sky map. Since this GW event has the second-smallest localization volume after GW170817, GW190814 is likely to provide the best constraint on cosmology from a single standard siren without identifying an electromagnetic counterpart. Our analysis uses photo-z probability distribution functions and corrects for photo-z biases. We also reanalyze the binary black hole GW170814 within this updated framework. We explore how our findings impact the H0 constraints from GW170817, the only GW merger associated with a unique host galaxy. From a combination of GW190814, GW170814, and GW170817, our analysis yields ${H}_{0}={72.0}_{-8.2}^{+12}\,\mathrm{km}\,{{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1}$ (68% highest-density interval, HDI) for a prior in H0 uniform between $[20\mathrm{and}140]\,\mathrm{km}\,{{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1}$ . The addition of GW190814 and GW170814 to GW170817 improves the 68% HDI from GW170817 alone by ∼18%, showing how well-localized mergers without counterparts can provide a significant contribution to standard siren measurements, provided that a complete galaxy catalog is available at the location of the event.
On the Diversity of Jet Production Efficiency in Swift/BAT AGNsRusinek, KatarzynaSikora, MarekKozieł-Wierzbowska, DorotaGupta, MaitrayeeDOI: info:10.3847/1538-4357/aba75fv. 900125
Rusinek, Katarzyna, Sikora, Marek, Kozieł-Wierzbowska, Dorota, and Gupta, Maitrayee. 2020. "On the Diversity of Jet Production Efficiency in Swift/BAT AGNs." The Astrophysical Journal 900:125. https://doi.org/10.3847/1538-4357/aba75f
ID: 157697
Type: article
Authors: Rusinek, Katarzyna; Sikora, Marek; Kozieł-Wierzbowska, Dorota; Gupta, Maitrayee
Abstract: We address the very large diversity of jet production efficiency in active galactic nuclei (AGNs) by using data on low-redshift AGNs selected from the Swift/BAT catalog and having black hole (BH) masses larger than 108.5 M. Most of these AGNs accrete at intermediate rates and have bolometric luminosities dominated by mid-IR radiation. Our sample contains 14% radio-loud (RL), 6% radio-intermediate, and 80% radio-quiet (RQ) AGNs. All RL objects are found to have extended radio structures, and most of them have classical FR II morphology. Converting their radio loudness to jet production efficiency, we find that the median of this efficiency is on the order of (∊d/0.1)%, where ${\epsilon }_{d}={L}_{\mathrm{bol}}/\dot{M}{c}^{2}$ is the radiation efficiency of the accretion disk. Without knowing the contribution of jets to the radio emission in RQ AGNs, we are only able to estimate their efficiencies using upper limits. Their median is found to be 0.002(∊d/0.1)%. Our results suggest that some threshold conditions must be satisfied to allow the production of strong, relativistic jets in RL AGNs. We discuss several possible scenarios and argue that the production of collimated, relativistic jets must involve the Blandford-Znajek mechanism and can be activated only in those AGNs whose lifetime is longer than the time required to enter the magnetically arrested disk (MAD). Presuming that MAD is required to collimate relativistic jets, we expect that the weak nonrelativistic jets observed in some RQ AGNs are produced by accretion disks rather than by rotating BHs.
Toward the RNA-World in the Interstellar Medium-Detection of Urea and Search of 2-Amino-oxazole and Simple SugarsJiménez-Serra, IzaskunMartín-Pintado, JesúsRivilla, Víctor M.Rodríguez-Almeida, LucasAlonso Alonso, Elena R.Zeng, ShaoshanCocinero, Emilio J.Martín, SergioRequena-Torres, MiguelMartín-Domenech, RafaelTesti, LeonardoDOI: info:10.1089/ast.2019.2125v. 201048–1066
Jiménez-Serra, Izaskun, Martín-Pintado, Jesús, Rivilla, Víctor M., Rodríguez-Almeida, Lucas, Alonso Alonso, Elena R., Zeng, Shaoshan, Cocinero, Emilio J., Martín, Sergio, Requena-Torres, Miguel, Martín-Domenech, Rafael, and Testi, Leonardo. 2020. "Toward the RNA-World in the Interstellar Medium-Detection of Urea and Search of 2-Amino-oxazole and Simple Sugars." Astrobiology 20:1048– 1066. https://doi.org/10.1089/ast.2019.2125
ID: 157698
Type: article
Authors: Jiménez-Serra, Izaskun; Martín-Pintado, Jesús; Rivilla, Víctor M.; Rodríguez-Almeida, Lucas; Alonso Alonso, Elena R.; Zeng, Shaoshan; Cocinero, Emilio J.; Martín, Sergio; Requena-Torres, Miguel; Martín-Domenech, Rafael; Testi, Leonardo
Abstract: In the past decade, astrochemistry has witnessed an impressive increase in the number of detections of complex organic molecules. Some of these species are of prebiotic interest such as glycolaldehyde, the simplest sugar, or aminoacetonitrile, a possible precursor of glycine. Recently, we have reported the detection of two new nitrogen-bearing complex organics, glycolonitrile and Z-cyanomethanimine, known to be intermediate species in the formation process of ribonucleotides within theories of a primordial RNA-world for the origin of life. In this study, we present deep and high-sensitivity observations toward two of the most chemically rich sources in the galaxy: a giant molecular cloud in the center of the Milky Way (G + 0.693-0.027) and a proto-Sun (IRAS16293-2422 B). Our aim is to explore whether the key precursors considered to drive the primordial RNA-world chemistry are also found in space. Our high-sensitivity observations reveal that urea is present in G + 0.693-0.027 with an abundance of ∼5 × 10-11. This is the first detection of this prebiotic species outside a star-forming region. Urea remains undetected toward the proto-Sun IRAS16293-2422 B (upper limit to its abundance of ≤2 × 10-11). Other precursors of the RNA-world chemical scheme such as glycolaldehyde or cyanamide are abundant in space, but key prebiotic species such as 2-amino-oxazole, glyceraldehyde, or dihydroxyacetone are not detected in either source. Future more sensitive observations targeting the brightest transitions of these species will be needed to disentangle whether these large prebiotic organics are certainly present in space.
PHAT XX. AGB Stars and Other Cool Giants in M31 Star ClustersGirardi, LéoBoyer, Martha L.Johnson, L. CliftonDalcanton, Julianne J.Rosenfield, PhilipSeth, Anil C.Skillman, Evan D.Weisz, Daniel R.Williams, Benjamin F.Bhattacharya, Antara RaaghaviBressan, AlessandroCaldwell, NelsonChen, YangDolphin, Andrew E.Fouesneau, MorganGoldman, StevenGuhathakurta, PuragraMarigo, PaolaMukherjee, SagnickPastorelli, GiadaQuirk, AmandaSoraisam, MonikaTrabucchi, MicheleDOI: info:10.3847/1538-4357/abad3av. 90119
Girardi, Léo, Boyer, Martha L., Johnson, L. Clifton, Dalcanton, Julianne J., Rosenfield, Philip, Seth, Anil C., Skillman, Evan D., Weisz, Daniel R., Williams, Benjamin F., Bhattacharya, Antara Raaghavi, Bressan, Alessandro, Caldwell, Nelson, Chen, Yang, Dolphin, Andrew E., Fouesneau, Morgan, Goldman, Steven, Guhathakurta, Puragra, Marigo, Paola, Mukherjee, Sagnick, Pastorelli, Giada, Quirk, Amanda, Soraisam, Monika, and Trabucchi, Michele. 2020. "PHAT XX. AGB Stars and Other Cool Giants in M31 Star Clusters." The Astrophysical Journal 901:19. https://doi.org/10.3847/1538-4357/abad3a
ID: 157699
Type: article
Authors: Girardi, Léo; Boyer, Martha L.; Johnson, L. Clifton; Dalcanton, Julianne J.; Rosenfield, Philip; Seth, Anil C.; Skillman, Evan D.; Weisz, Daniel R.; Williams, Benjamin F.; Bhattacharya, Antara Raaghavi; Bressan, Alessandro; Caldwell, Nelson; Chen, Yang; Dolphin, Andrew E.; Fouesneau, Morgan; Goldman, Steven; Guhathakurta, Puragra; Marigo, Paola; Mukherjee, Sagnick; Pastorelli, Giada; Quirk, Amanda; Soraisam, Monika; Trabucchi, Michele
Abstract: The presence of asymptotic giant branch (AGB) stars in clusters provides key constraints for stellar models, as has been demonstrated with historical data from the Magellanic Clouds. In this work, we look for candidate AGB stars in M31 star clusters from the Panchromatic Hubble Andromeda Treasury survey. Our photometric criteria selects stars brighter than the tip of the red giant branch, which includes the bulk of the thermally pulsing AGB stars as well as early-AGB stars and other luminous cool giants expected in young stellar populations (e.g., massive red supergiants, and intermediate-mass red helium-burning stars). The AGB stars can be differentiated, a posteriori, using the ages already estimated for our cluster sample. 937 candidates are found within the cluster aperture radii, half (∼450) of which are very likely cluster members. Cross-matching with additional databases reveals two carbon stars and 10 secure variables among them. The field-corrected age distribution reveals the presence of young supergiants peaking at ages smaller than 108 yr, followed by a long tail of AGB stars extending up to the oldest possible ages. This long tail reveals the general decrease in the numbers of AGB stars from initial values of $\sim 50\times {10}^{-6}{M}_{\odot }^{-1}$ at 108 yr down to $\sim 5\times {10}^{-6}{M}_{\odot }^{-1}$ at 1010 yr. Theoretical models of near-solar metallicity reproduce this general trend, although with localized discrepancies over some age intervals, whose origin is not yet identified. The entire catalog is released together with finding charts to facilitate follow-up studies.
A Gaia-based Catalog of Candidate Stripped Nuclei and Luminous Globular Clusters in the Halo of Centaurus AVoggel, Karina T.Seth, Anil C.Sand, David J.Hughes, AllisonStrader, JayCrnojevic, DenijaCaldwell, NelsonDOI: info:10.3847/1538-4357/ab6f69v. 899140
Voggel, Karina T., Seth, Anil C., Sand, David J., Hughes, Allison, Strader, Jay, Crnojevic, Denija, and Caldwell, Nelson. 2020. "A Gaia-based Catalog of Candidate Stripped Nuclei and Luminous Globular Clusters in the Halo of Centaurus A." The Astrophysical Journal 899:140. https://doi.org/10.3847/1538-4357/ab6f69
ID: 157700
Type: article
Authors: Voggel, Karina T.; Seth, Anil C.; Sand, David J.; Hughes, Allison; Strader, Jay; Crnojevic, Denija; Caldwell, Nelson
Abstract: Tidally stripped galaxy nuclei and luminous globular clusters (GCs) are important tracers of the halos and assembly histories of nearby galaxies, but are difficult to reliably identify with typical ground-based imaging data. In this paper we present a new method to find these massive star clusters using Gaia DR2, focusing on the massive elliptical galaxy Centaurus A (Cen A). We show that stripped nuclei and GCs are partially resolved by Gaia at the distance of Cen A, showing characteristic astrometric and photometric signatures. We use this selection method to produce a list of 632 new candidate luminous clusters in the halo of Cen A out to a projected radius of 150 kpc. Adding in broadband photometry and visual examination improves the accuracy of our classification. In a spectroscopic pilot program we have confirmed five new luminous clusters, which includes the 7th and 10th most luminous GC in Cen A. Three of the newly discovered GCs are further away from Cen A than all previously known GCs. Several of these are compelling candidates for stripped nuclei. We show that our novel Gaia selection method retains at least partial utility out to distances of ∼25 Mpc and hence is a powerful tool for finding and studying star clusters in the sparse outskirts of galaxies in the local universe.
Dust Populations in the Iconic Vega Planetary System Resolved by ALMAMatrà, LucaDent, William R. F.Wilner, David J.Marino, SebastiánWyatt, Mark C.Marshall, Jonathan P.Su, Kate Y. L.Chavez, MiguelHales, AntonioHughes, A. MeredithGreaves, Jane S.Corder, Stuartt A.DOI: info:10.3847/1538-4357/aba0a4v. 898146
Matrà, Luca, Dent, William R. F., Wilner, David J., Marino, Sebastián, Wyatt, Mark C., Marshall, Jonathan P., Su, Kate Y. L., Chavez, Miguel, Hales, Antonio, Hughes, A. Meredith, Greaves, Jane S., and Corder, Stuartt A. 2020. "Dust Populations in the Iconic Vega Planetary System Resolved by ALMA." The Astrophysical Journal 898:146. https://doi.org/10.3847/1538-4357/aba0a4
ID: 157701
Type: article
Authors: Matrà, Luca; Dent, William R. F.; Wilner, David J.; Marino, Sebastián; Wyatt, Mark C.; Marshall, Jonathan P.; Su, Kate Y. L.; Chavez, Miguel; Hales, Antonio; Hughes, A. Meredith; Greaves, Jane S.; Corder, Stuartt A.
Abstract: The Vega planetary system hosts the archetype of extrasolar Kuiper belts and is rich in dust from the sub-astronomical unit region out to hundreds of astronomical units, suggesting intense dynamical activity. We present Atacama Large Millimeter/submillimeter Array (ALMA) millimeter observations that detect and resolve the outer dust belt from the star for the first time. The interferometric visibilities show that the belt can be fit by a Gaussian model or by power-law models with a steep inner edge (at 60-80 au). The belt is very broad, extending out to at least 150-200 au. We strongly detect the star and set a stringent upper limit to warm dust emission previously detected in the infrared. We discuss three scenarios that could explain the architecture of Vega's planetary system, including the new ALMA constraints: no outer planets, a chain of low-mass planets, and a single giant planet. The planetless scenario is only feasible if the outer belt was born with the observed sharp inner edge. If, instead, the inner edge is currently being truncated by a planet, then the planet must be $\gtrsim 6$ ${M}_{\oplus }$ and at $\lesssim 71\,\mathrm{au}$ to have cleared its chaotic zone within the system age. In the planet chain scenario, outward planet migration and inward scattering of planetesimals could produce the hot and warm dust observed in the inner regions of the system. In the single giant planet scenario, an asteroid belt could be responsible for the warm dust, and mean motion resonances with the planet could put asteroids on star-grazing orbits, producing the hot dust.
TXS 0128+554: A Young Gamma-Ray-emitting Active Galactic Nucleus with Episodic Jet ActivityLister, Matthew L.Homan, Daniel C.Kovalev, Yuri Y.Mandal, S.Pushkarev, Alexander B.Siemiginowska, AnetaDOI: info:10.3847/1538-4357/aba18dv. 899141
Lister, Matthew L., Homan, Daniel C., Kovalev, Yuri Y., Mandal, S., Pushkarev, Alexander B., and Siemiginowska, Aneta. 2020. "TXS 0128+554: A Young Gamma-Ray-emitting Active Galactic Nucleus with Episodic Jet Activity." The Astrophysical Journal 899:141. https://doi.org/10.3847/1538-4357/aba18d
ID: 157702
Type: article
Authors: Lister, Matthew L.; Homan, Daniel C.; Kovalev, Yuri Y.; Mandal, S.; Pushkarev, Alexander B.; Siemiginowska, Aneta
Abstract: We have carried out a Chandra X-ray and multifrequency radio Very Long Baseline Array study of the active galactic nucleus (AGN) TXS 0128+554, which is associated with the Fermi γ-ray source 4FGL J0131.2+5547. The AGN is unresolved in a target 19.3 ks Chandra image, and its spectrum is well fit by a simple absorbed power-law model, with no distinguishable spectral features. Its relatively soft X-ray spectrum compared to other compact symmetric objects (CSOs) may be indicative of a thermal emission component, for which we were able to obtain an upper temperature limit of kT = 0.08 keV. The compact radio morphology and measured advance speed of 0.32 c ± 0.07 c indicate a kinematic age of only 82 yr ± 17 yr, placing TXS 0128+554 among the youngest members of the CSO class. The lack of compact, inverted spectrum hotspots and an emission gap between the bright inner jet and outer radio lobe structure indicate that the jets have undergone episodic activity, and were relaunched a decade ago. The predicted γ-ray emission from the lobes, based on an inverse Compton-emitting cocoon model, is three orders of magnitude below the observed Fermi-LAT flux. A comparison to other Fermi-detected and non-Fermi-detected CSOs with redshift z < 0.1 indicates that the γ-ray emission likely originates in the inner jet/core region, and that nearby, recently launched AGN jets are primary candidates for detection by the Fermi-LAT instrument.
X-Ray Properties of Young Radio Quasars at z > 4.5Snios, BradfordSiemiginowska, AnetaSobolewska, MałgosiaCheung, C. C.Kashyap, VinayMigliori, GiuliaSchwartz, Daniel A.Stawarz, ŁukaszWorrall, Diana M.DOI: info:10.3847/1538-4357/aba2cav. 899127
Snios, Bradford, Siemiginowska, Aneta, Sobolewska, Małgosia, Cheung, C. C., Kashyap, Vinay, Migliori, Giulia, Schwartz, Daniel A., Stawarz, Łukasz, and Worrall, Diana M. 2020. "X-Ray Properties of Young Radio Quasars at z > 4.5." The Astrophysical Journal 899:127. https://doi.org/10.3847/1538-4357/aba2ca
ID: 157703
Type: article
Authors: Snios, Bradford; Siemiginowska, Aneta; Sobolewska, Małgosia; Cheung, C. C.; Kashyap, Vinay; Migliori, Giulia; Schwartz, Daniel A.; Stawarz, Łukasz; Worrall, Diana M.
Abstract: We present a comprehensive analysis of Chandra X-ray observations of 15 young radio quasars at redshifts 4.5 45 erg s-1. The optical-X-ray power-law spectral index ${\alpha }_{\mathrm{ox}}$ is calculated for each source using optical/UV data available in the literature. The ${\alpha }_{\mathrm{ox}}$ -UV relationship is compared with other quasar surveys, and an anticorrelation is observed that agrees with independent estimates. Rest-frame radio and X-ray luminosities are established for the sample, and a correlation between the luminosities is detected. These multiwavelength results reinforce a lack of spectral evolution for quasars over a broad redshift range. We additionally identify three quasars from our multiwavelength analysis that are statistically significant outliers, with one source being a Compton-thick candidate in the early universe, and discuss each in detail.
Inverse-Compton scattering in the resolved jet of the high-redshift quasar PKS J1421-0643Worrall, D. M.Birkinshaw, M.Marshall, H. L.Schwartz, Daniel A.Siemiginowska, AnetaWardle, J. F. C.DOI: info:10.1093/mnras/staa1975v. 497988–1000
Worrall, D. M., Birkinshaw, M., Marshall, H. L., Schwartz, Daniel A., Siemiginowska, Aneta, and Wardle, J. F. C. 2020. "Inverse-Compton scattering in the resolved jet of the high-redshift quasar PKS J1421-0643." Monthly Notices of the Royal Astronomical Society 497:988– 1000. https://doi.org/10.1093/mnras/staa1975
ID: 157704
Type: article
Authors: Worrall, D. M.; Birkinshaw, M.; Marshall, H. L.; Schwartz, Daniel A.; Siemiginowska, Aneta; Wardle, J. F. C.
Abstract: Despite the fact that kpc-scale inverse-Compton (iC) scattering of cosmic microwave background (CMB) photons into the X-ray band is mandated, proof of detection in resolved quasar jets is often insecure. High redshift provides favourable conditions due to the increased energy density of the CMB, and it allows constraints to be placed on the radio synchrotron-emitting electron component at high energies that are otherwise inaccessible. We present new X-ray, optical, and radio results from Chandra, HST, and the VLA for the core and resolved jet in the z = 3.69 quasar PKS J1421-0643. The X-ray jet extends for about 4.5 arcsec (32 kpc projected length). The jet's radio spectrum is abnormally steep and consistent with electrons being accelerated to a maximum Lorentz factor of about 5000. Results argue in favour of the detection of iC X-rays for modest magnetic field strength of a few nT, Doppler factor of about 4, and viewing angle of about 15°, and predict the jet to be largely invisible in most other spectral bands including the far- and mid-infrared and high-energy gamma-ray. The jet power is estimated to be about 3 × 1046 erg s-1 which is of order a tenth of the quasar bolometric power, for an electron-positron jet. The jet radiative power is only about 0.07 per cent of the jet power, with a smaller radiated power ratio if the jet contains heavy particles, so most of the jet power is available for heating the intergalactic medium.
Mid-infrared Diagnostics of the Circumnuclear Environments of the Youngest Radio GalaxiesKosmaczewski, E.Stawarz, Ł.Siemiginowska, AnetaCheung, C. C.Ostorero, L.Sobolewska, MalgorzataKozieł-Wierzbowska, D.Wójtowicz, A.Marchenko, V.DOI: info:10.3847/1538-4357/ab9b1fv. 897164
Kosmaczewski, E., Stawarz, Ł., Siemiginowska, Aneta, Cheung, C. C., Ostorero, L., Sobolewska, Malgorzata, Kozieł-Wierzbowska, D., Wójtowicz, A., and Marchenko, V. 2020. "Mid-infrared Diagnostics of the Circumnuclear Environments of the Youngest Radio Galaxies." The Astrophysical Journal 897:164. https://doi.org/10.3847/1538-4357/ab9b1f
ID: 157705
Type: article
Authors: Kosmaczewski, E.; Stawarz, Ł.; Siemiginowska, Aneta; Cheung, C. C.; Ostorero, L.; Sobolewska, Malgorzata; Kozieł-Wierzbowska, D.; Wójtowicz, A.; Marchenko, V.
Abstract: We present a systematic analysis of the mid-infrared (MIR) properties of the youngest radio galaxies, based on low-resolution data provided by the Wide-field Infrared Survey Explorer and IRAS satellites. We restrict our analysis to sources with available X-ray data that constitute the earliest phase of radio galaxy evolution, I.e., those classified as gigahertz-peaked spectrum and/or compact symmetric objects. In our sample of 29 objects, we find that the host galaxies are predominantly red/yellow ellipticals, with some of them displaying distorted morphology. We find a variety of MIR colors and observe that the sources in which the MIR emission is dominated by the ISM component uniformly populate the region occupied by galaxies with a wide range of pronounced (≥0.5M yr-1) star formation activity. We compare the MIR color distribution in our sample to that in the general population of local active galactic nuclei (AGNs), in the population of evolved FR II radio galaxies, and also in the population of radio galaxies with recurrent jet activity. We conclude that the triggering of radio jets in AGNs does not differentiate between elliptical hosts with substantially different fractions of young stars; instead, there is a relationship between the jet duty cycle and the ongoing star formation. The distribution of the subsample of our sources with z < 0.4 on the low-resolution MIR versus absorption-corrected X-ray luminosity plane is consistent with the distribution of a sample of local AGNs. Finally, we comment on the star formation rates of the two γ-ray-detected sources in our sample, 1146+596 and 1718-649.
SPISEA: A Python-based Simple Stellar Population Synthesis Code for Star ClustersHosek, Matthew W., Jr.Lu, Jessica R.Lam, Casey Y.Gautam, Abhimat K.Lockhart, Kelly E.Kim, DongwonJia, SiyaoDOI: info:10.3847/1538-3881/aba533v. 160143
Hosek, Matthew W., Jr., Lu, Jessica R., Lam, Casey Y., Gautam, Abhimat K., Lockhart, Kelly E., Kim, Dongwon, and Jia, Siyao. 2020. "SPISEA: A Python-based Simple Stellar Population Synthesis Code for Star Clusters." The Astronomical Journal 160:143. https://doi.org/10.3847/1538-3881/aba533
ID: 157706
Type: article
Authors: Hosek, Matthew W., Jr.; Lu, Jessica R.; Lam, Casey Y.; Gautam, Abhimat K.; Lockhart, Kelly E.; Kim, Dongwon; Jia, Siyao
Abstract: We present Stellar Population Interface for Stellar Evolution and Atmospheres (SPISEA), an open-source Python package that simulates simple stellar populations. The strength of SPISEA is its modular interface which offers the user control of 13 input properties including (but not limited to) the initial mass function, stellar multiplicity, extinction law, and the metallicity-dependent stellar evolution and atmosphere model grids used. The user also has control over the initial-final mass relation in order to produce compact stellar remnants (black holes, neutron stars, and white dwarfs). We demonstrate several outputs produced by the code, including color-magnitude diagrams, HR-diagrams, luminosity functions, and mass functions. SPISEA is object-oriented and extensible, and we welcome contributions from the community. The code and documentation are available on GitHub (https://github.com/astropy/SPISEA) and ReadtheDocs (https://spisea.readthedocs.io/en/latest/), respectively.
Plasma Diagnostics of the Supernova Remnant N132D using Deep XMM-Newton Observations with the Reflection Grating SpectrometerSuzuki, HitomiYamaguchi, HiroyaIshida, ManabuUchida, HiroyukiPlucinsky, Paul P.Foster, Adam R.Miller, Eric D.DOI: info:10.3847/1538-4357/aba524v. 90039
Suzuki, Hitomi, Yamaguchi, Hiroya, Ishida, Manabu, Uchida, Hiroyuki, Plucinsky, Paul P., Foster, Adam R., and Miller, Eric D. 2020. "Plasma Diagnostics of the Supernova Remnant N132D using Deep XMM-Newton Observations with the Reflection Grating Spectrometer." The Astrophysical Journal 900:39. https://doi.org/10.3847/1538-4357/aba524
ID: 157707
Type: article
Authors: Suzuki, Hitomi; Yamaguchi, Hiroya; Ishida, Manabu; Uchida, Hiroyuki; Plucinsky, Paul P.; Foster, Adam R.; Miller, Eric D.
Abstract: We present XMM-Newton observations of N132D, the X-ray brightest supernova remnant in the Large Magellanic Cloud, using the Reflection Grating Spectrometer (RGS), which enables high-resolution spectroscopy in the soft X-ray band. A dozen emission lines from L-shell transitions of Si, S, Ar, Ca, and Fe at intermediate charge states are newly detected in the RGS data integrating the ∼200 ks on-axis observations. This enables accurate abundance measurements of these elements, whose K-shell emission is out of the RGS bandpass. The 0.3-2.0-keV spectra require at least three components of thermal plasmas with different electron temperatures and indicate clear evidence of non-equilibrium ionization (NEI). Our detailed spectral diagnostics further reveal that the forbidden-to-resonance line ratios of O VII and Ne IX are both higher than expected for typical NEI plasmas. This enhancement could be attributed to either resonance scattering or emission induced by charge exchange in addition to a possible contribution from the superposition of multiple-temperature components, although the lack of spatial information prevents us from concluding which is most likely.
Element Stratification in the Middle-aged SN Ia Remnant G344.7-0.1Fukushima, KotaroYamaguchi, HiroyaSlane, Patrick O.Park, SangwookKatsuda, SatoruSano, HidetoshiLopez, Laura A.Plucinsky, Paul P.Kobayashi, Shogo B.Matsushita, KyokoDOI: info:10.3847/1538-4357/ab94a6v. 89762
Fukushima, Kotaro, Yamaguchi, Hiroya, Slane, Patrick O., Park, Sangwook, Katsuda, Satoru, Sano, Hidetoshi, Lopez, Laura A., Plucinsky, Paul P., Kobayashi, Shogo B., and Matsushita, Kyoko. 2020. "Element Stratification in the Middle-aged SN Ia Remnant G344.7-0.1." The Astrophysical Journal 897:62. https://doi.org/10.3847/1538-4357/ab94a6
ID: 157708
Type: article
Authors: Fukushima, Kotaro; Yamaguchi, Hiroya; Slane, Patrick O.; Park, Sangwook; Katsuda, Satoru; Sano, Hidetoshi; Lopez, Laura A.; Plucinsky, Paul P.; Kobayashi, Shogo B.; Matsushita, Kyoko
Abstract: Despite their importance, a detailed understanding of Type Ia supernovae (SNe Ia) remains elusive. X-ray measurements of the element distributions in supernova remnants (SNRs) offer important clues for understanding the explosion and nucleosynthesis mechanisms for SNe Ia. However, it is challenging to observe the entire ejecta mass in X-rays for young SNRs, because the central ejecta may not have been heated by the reverse shock yet. Here we present over 200 kilosecond Chandra observations of the Type Ia SNR G344.7-0.1, whose age is old enough for the reverse shock to have reached the SNR center, providing an opportunity to investigate the distribution of the entire ejecta mass. We reveal a clear stratification of heavy elements with a centrally peaked distribution of the Fe ejecta surrounded by intermediate-mass elements (IMEs: Si, S, Ar Ca) with an arc-like structure. The centroid energy of the Fe K emission is marginally lower in the central Fe-rich region than in the outer IME-rich regions, suggesting that the Fe ejecta were shock-heated more recently. These results are consistent with the prediction for standard SN Ia models, where the heavier elements are synthesized in the interior of an exploding white dwarf. We find, however, that the peak location of the Fe K emission is slightly offset to the west with respect to the geometric center of the SNR. This apparent asymmetry is likely due to the inhomogeneous density distribution of the ambient medium, consistent with our radio observations of the ambient molecular and neutral gas.
Uncovering Magnetic Turbulence in Young Supernova Remnants with Polarized X-Ray ImagingBykov, Andrei M.Uvarov, Yury A.Slane, PatrickEllison, Donald C.DOI: info:10.3847/1538-4357/aba960v. 899142
Bykov, Andrei M., Uvarov, Yury A., Slane, Patrick, and Ellison, Donald C. 2020. "Uncovering Magnetic Turbulence in Young Supernova Remnants with Polarized X-Ray Imaging." The Astrophysical Journal 899:142. https://doi.org/10.3847/1538-4357/aba960
ID: 157709
Type: article
Authors: Bykov, Andrei M.; Uvarov, Yury A.; Slane, Patrick; Ellison, Donald C.
Abstract: Observations of young supernova remnants (SNRs) in X-rays and γ-rays have provided conclusive evidence for particle acceleration to at least TeV energies. Analysis of high-spatial-resolution X-ray maps of young SNRs has indicated that the particle acceleration process is accompanied by strong nonadiabatic amplification of magnetic fields. If Fermi acceleration is the mechanism producing the energetic cosmic rays (CRs), the amplified magnetic field must be turbulent, and CR-driven instabilities are among the most probable mechanisms for converting the shock ram pressure into magnetic turbulence. The development and evolution of strong magnetic turbulence in collisionless plasmas forming SNR shells are complicated phenomena which include the amplification of magnetic modes, anisotropic mode transformations at shocks, as well as the nonlinear physics of turbulent cascades. Polarized X-ray synchrotron radiation from ultrarelativistic electrons accelerated in the SNR shock is produced in a thin layer immediately behind the shock and is not subject to the Faraday depolarization effect. These factors open up possibilities to study some properties of magnetic turbulence, and here we present polarized X-ray synchrotron maps of SNR shells assuming different models of magnetic turbulence cascades. It is shown that different models of anisotropic turbulence can be distinguished by measuring the predominant polarization angle direction. We discuss the detection of these features in Tycho's SNR with the coming generation of X-ray polarimeters such as the Imaging X-ray Polarimetry Explorer.
Quasi-Optical Characterization of Low-Loss Polymers at 300 GHz for Vacuum Window ApplicationsTong, Cheuk-Yu EdwardCarter, KearaConnors, JakeDOI: info:10.1109/TTHZ.2020.3021352v. 10No. 6713–720
Tong, Cheuk-Yu Edward, Carter, Keara, and Connors, Jake. 2020. "Quasi-Optical Characterization of Low-Loss Polymers at 300 GHz for Vacuum Window Applications." Ieee Transactions on Terahertz Science and Technology 10 (6):713– 720. https://doi.org/10.1109/TTHZ.2020.3021352
ID: 157633
Type: article
Authors: Tong, Cheuk-Yu Edward; Carter, Keara; Connors, Jake
Abstract: We report on the measurements of the complex refractive index of a number of low-loss polymers using a quasi-optical vector network analyzer operating in the frequency range of 210-370 GHz. The process of extracting both the real and imaginary parts of the refractive indexes is presented in this article, along with the method of error estimation. The measured refractive indexes of 25 different material samples, as well as the estimated error and the loss tangents of thicker samples, are tabulated. For selected materials, loss tangents have also been confirmed using the method of intersecting lines, which measures the additional input noise to a superconductor-insulator-superconductor receiver due to the dielectric sample. The data obtained from this work will be useful for the design of low-loss vacuum windows for cryogenic receivers operating in the 300-GHz range.
The Influence of LO Power Heating of the Tunnel Junction on the Performance of THz SIS MixersTraini, AlessandroTan, Boon-KokGarrett, John D.Khudchenko, AndreyHesper, RonaldBaryshev, Andrey M.Dmitriev, Pavel N.Koshelets, Valery P.Yassin, GhassanDOI: info:10.1109/TTHZ.2020.3028028v. 10No. 6721–730
Traini, Alessandro, Tan, Boon-Kok, Garrett, John D., Khudchenko, Andrey, Hesper, Ronald, Baryshev, Andrey M., Dmitriev, Pavel N., Koshelets, Valery P., and Yassin, Ghassan. 2020. "The Influence of LO Power Heating of the Tunnel Junction on the Performance of THz SIS Mixers." Ieee Transactions on Terahertz Science and Technology 10 (6):721– 730. https://doi.org/10.1109/TTHZ.2020.3028028
ID: 157634
Type: article
Authors: Traini, Alessandro; Tan, Boon-Kok; Garrett, John D.; Khudchenko, Andrey; Hesper, Ronald; Baryshev, Andrey M.; Dmitriev, Pavel N.; Koshelets, Valery P.; Yassin, Ghassan
Abstract: We describe the performance of a superconductor-insulator-superconductor (SIS) mixer operating in the frequency range of 780-950 GHz. Unlike most SIS mixers, the tunnel junction employs two different superconductors, a niobium nitride top and a niobium bottom electrode sandwiching an aluminum nitride barrier layer, fabricated on a niobium titanium nitride ground plane. The mixer was tested in a pulse tube cryostat, with all the optical components, in the signal path, mounted inside the vacuum environment to avoid attenuation of the RF signal as it propagates from the hot/cold loads to the mixer. With this setup, we have measured an RF-corrected noise temperature of similar to 220 K. In this article, we focus on investigating the influence of local oscillator (LO) power heating on the performance of the terahertz mixer. The increase in the junction's physical temperature can be observed experimentally by noting the suppression of the gap voltage in the pumped current-voltage (I-V) curve as the LO pumping level is increased. Similar observation has already been reported, and attempts were made to estimate the effective temperature of the device using equations of heat transfer between the mixer chip layers. Here, we present an experimental method of quantifying this effect by recovering the effective temperature of the junction through comparing the pumped I-V curves at different pumping levels and fixed bath temperature, with the unpumped I-V curves obtained at varying bath temperatures. We also estimate, for the first time, the effect of heating on the noise temperature as a function of bath temperature and frequency. We show that for typical experimental parameters, the LO heating can increase the double-side-band receiver noise temperature by as much as 20%, and that in the frequency range of the measurements, the effective temperature of the junction at fixed LO power increases linearly with frequency at a rate of 0.5 K/100 GHz.
Plasma Double Layers at the Boundary Between Venus and the Solar WindMalaspina, D. M.Goodrich, K.Livi, R.Halekas, J.McManus, M.Curry, S.Bale, S. D.Bonnell, J. W.Wit, T. DudokGoetz, K.Harvey, P. R.MacDowall, R. J.Pulupa, M.Case, Anthony W.Kasper, J. C.Korreck, Kelly E.Larson, D.Stevens, Michael L.Whittlesey, P.DOI: info:10.1029/2020GL090115v. 47No. 20e2020GL090115–e2020GL090115
Malaspina, D. M., Goodrich, K., Livi, R., Halekas, J., McManus, M., Curry, S., Bale, S. D., Bonnell, J. W., Wit, T. Dudok, Goetz, K., Harvey, P. R., MacDowall, R. J., Pulupa, M., Case, Anthony W., Kasper, J. C., Korreck, Kelly E., Larson, D., Stevens, Michael L., and Whittlesey, P. 2020. "Plasma Double Layers at the Boundary Between Venus and the Solar Wind." Geophysical Research Letters 47 (20):e2020GL090115– e2020GL090115. https://doi.org/10.1029/2020GL090115
ID: 157636
Type: article
Authors: Malaspina, D. M.; Goodrich, K.; Livi, R.; Halekas, J.; McManus, M.; Curry, S.; Bale, S. D.; Bonnell, J. W.; Wit, T. Dudok; Goetz, K.; Harvey, P. R.; MacDowall, R. J.; Pulupa, M.; Case, Anthony W.; Kasper, J. C.; Korreck, Kelly E.; Larson, D.; Stevens, Michael L.; Whittlesey, P.
Abstract: The solar wind is slowed, deflected, and heated as it encounters Venus's induced magnetosphere. The importance of kinetic plasma processes to these interactions has not been examined in detail, due to a lack of constraining observations. In this study, kinetic-scale electric field structures are identified in the Venusian magnetosheath, including plasma double layers. The double layers may be driven by currents or mixing of inhomogeneous plasmas near the edge of the magnetosheath. Estimated double-layer spatial scales are consistent with those reported at Earth. Estimated potential drops are similar to electron temperature gradients across the bow shock. Many double layers are found in few high cadence data captures, suggesting that their amplitudes are high relative to other magnetosheath plasma waves. These are the first direct observations of plasma double layers beyond near-Earth space, supporting the idea that kinetic plasma processes are active in many space plasma environments.
A Hard Look at Local, Optically Selected, Obscured Seyfert GalaxiesKammoun, E. S.Miller, J. M.Koss, M.Oh, K.Zoghbi, A.Mushotzky, R. F.Barret, D.Behar, E.Brandt, W. N.Brenneman, Laura W.Kaastra, J. S.Lohfink, A. M.Proga, D.Stern, D.DOI: info:10.3847/1538-4357/abb29fv. 901161
Kammoun, E. S., Miller, J. M., Koss, M., Oh, K., Zoghbi, A., Mushotzky, R. F., Barret, D., Behar, E., Brandt, W. N., Brenneman, Laura W., Kaastra, J. S., Lohfink, A. M., Proga, D., and Stern, D. 2020. "A Hard Look at Local, Optically Selected, Obscured Seyfert Galaxies." The Astrophysical Journal 901:161. https://doi.org/10.3847/1538-4357/abb29f
ID: 157611
Type: article
Authors: Kammoun, E. S.; Miller, J. M.; Koss, M.; Oh, K.; Zoghbi, A.; Mushotzky, R. F.; Barret, D.; Behar, E.; Brandt, W. N.; Brenneman, Laura W.; Kaastra, J. S.; Lohfink, A. M.; Proga, D.; Stern, D.
Abstract: We study the X-ray spectra of a sample of 19 obscured, optically selected Seyfert galaxies (Sy 1.8, 1.9, and 2) in the local universe (d ≤ 175 Mpc), drawn from the CfA Seyfert sample. Our analysis is driven by the high sensitivity of NuSTAR in the hard X-rays, coupled with soft X-ray spectra using XMM-Newton, Chandra, Suzaku, and Swift/XRT. We also analyze the optical spectra of these sources in order to obtain accurate mass estimates and Eddington fractions. We employ four different models to analyze the X-ray spectra of these sources, which all provide consistent results. We find that 79%-90% of the sources are heavily obscured with line-of-sight column density NH > 1023 cm-2. We also find a Compton-thick (NH > 1024 cm-2) fraction of 37%-53%. These results are consistent with previous estimates based on multiwavelength analyses. We find that the fraction of reprocessed to intrinsic emission is positively correlated with NH and negatively correlated with the intrinsic, unabsorbed X-ray luminosity (in agreement with the Iwasawa-Taniguchi effect). Our results support the hypothesis that radiation pressure regulates the distribution of the circumnuclear material. * Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under program ID 099.A-0403.
An Earth-like Stellar Wind Environment for Proxima Centauri cAlvarado-Gómez, Julián D.Drake, Jeremy J.Garraffo, CeciliaCohen, OferPoppenhaeger, KatjaYadav, Rakesh K.Moschou, Sofia P.DOI: info:10.3847/2041-8213/abb885v. 902L9
Alvarado-Gómez, Julián D., Drake, Jeremy J., Garraffo, Cecilia, Cohen, Ofer, Poppenhaeger, Katja, Yadav, Rakesh K., and Moschou, Sofia P. 2020. "An Earth-like Stellar Wind Environment for Proxima Centauri c." The Astrophysical Journal 902:L9. https://doi.org/10.3847/2041-8213/abb885
ID: 157612
Type: article
Authors: Alvarado-Gómez, Julián D.; Drake, Jeremy J.; Garraffo, Cecilia; Cohen, Ofer; Poppenhaeger, Katja; Yadav, Rakesh K.; Moschou, Sofia P.
Abstract: A new planet has been recently discovered around Proxima Centauri. With an orbital separation of ∼1.44 au and a minimum mass of about $7\,{M}_{\oplus }$ , Proxima c is a prime direct imaging target for atmospheric characterization. The latter can only be performed with a good understanding of the space environment of the planet, as multiple processes can have profound effects on the atmospheric structure and evolution. Here, we take one step in this direction by generating physically realistic numerical simulations of Proxima's stellar wind, coupled to a magnetosphere and ionosphere model around Proxima c. We evaluate their expected variation due to the magnetic cycle of the host star, as well as for plausible inclination angles for the exoplanet orbit. Our results indicate stellar wind dynamic pressures comparable to present-day Earth, with a slight increase (by a factor of 2) during high-activity periods of the star. A relatively weak interplanetary magnetic field at the distance of Proxima c leads to negligible stellar wind Joule heating of the upper atmosphere (about 10% of the solar wind contribution on Earth) for an Earth-like planetary magnetic field (0.3 G). Finally, we provide an assessment of the likely extreme conditions experienced by the exoplanet candidate Proxima d, tentatively located at 0.029 au with a minimum mass of 0.29 M.
Erratum: 'Far-infrared to Millimeter Data of Protoplanetary Disks: Dust Growth in the Taurus, Ophiuchus, and Chamaeleon I Star-forming Regions' (2017, ApJ, 849, 63)Ribas, ÁlvaroEspaillat, Catherine C.Macías, EnriqueBouy, HervéAndrews, SeanCalvet, NuriaNaylor, David A.Riviere-Marichalar, Pablovan der Wiel, Matthijs H. D.Wilner, DavidDOI: info:10.3847/1538-4357/abb66ev. 90188
Ribas, Álvaro, Espaillat, Catherine C., Macías, Enrique, Bouy, Hervé, Andrews, Sean, Calvet, Nuria, Naylor, David A., Riviere-Marichalar, Pablo, van der Wiel, Matthijs H. D., and Wilner, David. 2020. "Erratum: "Far-infrared to Millimeter Data of Protoplanetary Disks: Dust Growth in the Taurus, Ophiuchus, and Chamaeleon I Star-forming Regions" (2017, ApJ, 849, 63)." The Astrophysical Journal 901:88. https://doi.org/10.3847/1538-4357/abb66e
ID: 157613
Type: article
Authors: Ribas, Álvaro; Espaillat, Catherine C.; Macías, Enrique; Bouy, Hervé; Andrews, Sean; Calvet, Nuria; Naylor, David A.; Riviere-Marichalar, Pablo; van der Wiel, Matthijs H. D.; Wilner, David
The Multiplanet System TOI-421Carleo, IlariaGandolfi, DavideBarragán, OscarLivingston, John H.Persson, Carina M.Lam, Kristine W. F.Vidotto, AlineLund, Michael B.D'Angelo, Carolina VillarrealCollins, Karen A.Fossati, LucaHoward, Andrew W.Kubyshkina, DariaBrahm, RafaelOklopčić, AntonijaMollière, PaulRedfield, SethSerrano, Luisa MariaDai, FeiFridlund, MalcolmBorsa, FrancescoKorth, JudithEsposito, MassimilianoDíaz, Matías R.Nielsen, Louise DyregaardHellier, CoelMathur, SavitaDeeg, Hans J.Hatzes, Artie P.Benatti, SerenaRodler, FlorianAlarcon, JavierSpina, LorenzoSantos, Ângela R. G.Georgieva, IskraGarcía, Rafael A.González-Cuesta, LucíaRicker, George R.Vanderspek, RolandLatham, David W.Seager, SaraWinn, Joshua N.Jenkins, Jon M.Albrecht, SimonBatalha, Natalie M.Beard, CoreyBoyd, Patricia T.Bouchy, FrançoisBurt, Jennifer A.Butler, R. PaulCabrera, JuanChontos, AshleyCiardi, David R.Cochran, William D.Collins, Kevin I.Crane, Jeffrey D.Crossfield, IanCsizmadia, SzilardDragomir, DianaDressing, CourtneyEigmüller, PhilippEndl, MichaelErikson, AndersEspinoza, NestorFausnaugh, MichaelFeng, FaboFlowers, ErinFulton, BenjaminGonzales, Erica J.Grieves, NolanGrziwa, SaschaGuenther, Eike W.Guerrero, Natalia M.Henning, ThomasHidalgo, DiegoHirano, TeruyukiHjorth, MariaHuber, DanielIsaacson, HowardJones, MatiasJordán, AndrésKabáth, PetrKane, Stephen R.Knudstrup, EmilLubin, JackLuque, RafaelMireles, IsmaelNarita, NorioNespral, DavidNiraula, PrajwalNowak, GrzegorzPalle, EnricPätzold, MartinPetigura, Erik A.Prieto-Arranz, JorgeRauer, HeikeRobertson, PaulRose, Mark E.Roy, ArpitaSarkis, PaulaSchlieder, Joshua E.Ségransan, DamienShectman, StephenSkarka, MarekSmith, Alexis M. S.Smith, Jeffrey C.Stassun, KeivanTeske, JohannaTwicken, Joseph D.Eylen, Vincent VanWang, SharonWeiss, Lauren M.Wyttenbach, AurélienDOI: info:10.3847/1538-3881/aba124v. 160114
Carleo, Ilaria, Gandolfi, Davide, Barragán, Oscar, Livingston, John H., Persson, Carina M., Lam, Kristine W. F., Vidotto, Aline, Lund, Michael B., D'Angelo, Carolina Villarreal, Collins, Karen A., Fossati, Luca, Howard, Andrew W., Kubyshkina, Daria, Brahm, Rafael, Oklopčić, Antonija, Mollière, Paul, Redfield, Seth, Serrano, Luisa Maria, Dai, Fei, Fridlund, Malcolm, Borsa, Francesco, Korth, Judith, Esposito, Massimiliano, Díaz, Matías R., Nielsen, Louise Dyregaard et al. 2020. "The Multiplanet System TOI-421." The Astronomical Journal 160:114. https://doi.org/10.3847/1538-3881/aba124
ID: 157614
Type: article
Authors: Carleo, Ilaria; Gandolfi, Davide; Barragán, Oscar; Livingston, John H.; Persson, Carina M.; Lam, Kristine W. F.; Vidotto, Aline; Lund, Michael B.; D'Angelo, Carolina Villarreal; Collins, Karen A.; Fossati, Luca; Howard, Andrew W.; Kubyshkina, Daria; Brahm, Rafael; Oklopčić, Antonija; Mollière, Paul; Redfield, Seth; Serrano, Luisa Maria; Dai, Fei; Fridlund, Malcolm; Borsa, Francesco; Korth, Judith; Esposito, Massimiliano; Díaz, Matías R.; Nielsen, Louise Dyregaard; Hellier, Coel; Mathur, Savita; Deeg, Hans J.; Hatzes, Artie P.; Benatti, Serena; Rodler, Florian; Alarcon, Javier; Spina, Lorenzo; Santos, Ângela R. G.; Georgieva, Iskra; García, Rafael A.; González-Cuesta, Lucía; Ricker, George R.; Vanderspek, Roland; Latham, David W.; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Albrecht, Simon; Batalha, Natalie M.; Beard, Corey; Boyd, Patricia T.; Bouchy, François; Burt, Jennifer A.; Butler, R. Paul; Cabrera, Juan; Chontos, Ashley; Ciardi, David R.; Cochran, William D.; Collins, Kevin I.; Crane, Jeffrey D.; Crossfield, Ian; Csizmadia, Szilard; Dragomir, Diana; Dressing, Courtney; Eigmüller, Philipp; Endl, Michael; Erikson, Anders; Espinoza, Nestor; Fausnaugh, Michael; Feng, Fabo; Flowers, Erin; Fulton, Benjamin; Gonzales, Erica J.; Grieves, Nolan; Grziwa, Sascha; Guenther, Eike W.; Guerrero, Natalia M.; Henning, Thomas; Hidalgo, Diego; Hirano, Teruyuki; Hjorth, Maria; Huber, Daniel; Isaacson, Howard; Jones, Matias; Jordán, Andrés; Kabáth, Petr; Kane, Stephen R.; Knudstrup, Emil; Lubin, Jack; Luque, Rafael; Mireles, Ismael; Narita, Norio; Nespral, David; Niraula, Prajwal; Nowak, Grzegorz; Palle, Enric; Pätzold, Martin; Petigura, Erik A.; Prieto-Arranz, Jorge; Rauer, Heike; Robertson, Paul; Rose, Mark E.; Roy, Arpita; Sarkis, Paula; Schlieder, Joshua E.; Ségransan, Damien; Shectman, Stephen; Skarka, Marek; Smith, Alexis M. S.; Smith, Jeffrey C.; Stassun, Keivan; Teske, Johanna; Twicken, Joseph D.; Eylen, Vincent Van; Wang, Sharon; Weiss, Lauren M.; Wyttenbach, Aurélien
Abstract: We report the discovery of a warm Neptune and a hot sub-Neptune transiting TOI-421 (BD-14 1137, TIC 94986319), a bright (V = 9.9) G9 dwarf star in a visual binary system observed by the Transiting Exoplanet Survey Satellite (TESS) space mission in Sectors 5 and 6. We performed ground-based follow-up observations-comprised of Las Cumbres Observatory Global Telescope transit photometry, NIRC2 adaptive optics imaging, and FIbre-fed Echellé Spectrograph, CORALIE, High Accuracy Radial velocity Planet Searcher, High Resolution Échelle Spectrometer, and Planet Finder Spectrograph high-precision Doppler measurements-and confirmed the planetary nature of the 16 day transiting candidate announced by the TESS team. We discovered an additional radial velocity signal with a period of five days induced by the presence of a second planet in the system, which we also found to transit its host star. We found that the inner mini-Neptune, TOI-421 b, has an orbital period of Pb = 5.19672 ± 0.00049 days, a mass of Mb = 7.17 ± 0.66 M, and a radius of Rb = ${2.68}_{-0.18}^{+0.19}$ R, whereas the outer warm Neptune, TOI-421 c, has a period of Pc = 16.06819 ± 0.00035 days, a mass of Mc = ${16.42}_{-1.04}^{+1.06}$ M, a radius of Rc = ${5.09}_{-0.15}^{+0.16}$ R, and a density of ρc = ${0.685}_{-0.072}^{+0.080}$ g cm-3. With its characteristics, the outer planet (ρc = ${0.685}_{-0.072}^{+0.080}$ g cm-3) is placed in the intriguing class of the super-puffy mini-Neptunes. TOI-421 b and TOI-421 c are found to be well-suited for atmospheric characterization. Our atmospheric simulations predict significant Lyα transit absorption, due to strong hydrogen escape in both planets, as well as the presence of detectable CH4 in the atmosphere of TOI-421 c if equilibrium chemistry is assumed. * Based on observations made with ESO Telescopes at the La Silla Observatory under programs ID 1102.C-0923, 0103.C-0874, 0103.C-0759, 0103.C-0442, and 60.A-970. Based on observations obtained with the Nordic Optical Telescope (NOT), operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos (ORM) of the Instituto de Astrofísica de Canarias (IAC). This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. This work makes use of observations from the LCOGT network.
The First Habitable-zone Earth-sized Planet from TESS. III. Climate States and Characterization Prospects for TOI-700 dSuissa, GabrielleWolf, Eric T.Kopparapu, Ravi KumarVillanueva, Geronimo L.Fauchez, ThomasMandell, Avi M.Arney, GiadaGilbert, Emily A.Schlieder, Joshua E.Barclay, ThomasQuintana, Elisa V.Lopez, EricRodriguez, Joseph E.Vanderburg, AndrewDOI: info:10.3847/1538-3881/aba4b4v. 160118
Suissa, Gabrielle, Wolf, Eric T., Kopparapu, Ravi Kumar, Villanueva, Geronimo L., Fauchez, Thomas, Mandell, Avi M., Arney, Giada, Gilbert, Emily A., Schlieder, Joshua E., Barclay, Thomas, Quintana, Elisa V., Lopez, Eric, Rodriguez, Joseph E., and Vanderburg, Andrew. 2020. "The First Habitable-zone Earth-sized Planet from TESS. III. Climate States and Characterization Prospects for TOI-700 d." The Astronomical Journal 160:118. https://doi.org/10.3847/1538-3881/aba4b4
ID: 157615
Type: article
Authors: Suissa, Gabrielle; Wolf, Eric T.; Kopparapu, Ravi Kumar; Villanueva, Geronimo L.; Fauchez, Thomas; Mandell, Avi M.; Arney, Giada; Gilbert, Emily A.; Schlieder, Joshua E.; Barclay, Thomas; Quintana, Elisa V.; Lopez, Eric; Rodriguez, Joseph E.; Vanderburg, Andrew
Abstract: We present self-consistent three-dimensional climate simulations of possible habitable states for the newly discovered habitable-zone Earth-sized planet TOI-700 d. We explore a variety of atmospheric compositions, pressures, and rotation states for both ocean-covered and completely desiccated planets in order to assess the planet's potential for habitability. For all 20 of our simulated cases, we use our climate model outputs to synthesize transmission spectra, combined-light spectra, and integrated broadband phase curves. These climatologically informed observables will help the community assess the technological capabilities necessary for future characterization of this planet-as well as similar transiting planets discovered in the future-and will provide a guide for distinguishing possible climate states if one day we do obtain sensitive spectral observations of a habitable planet around an M star. We find that TOI-700 d is a strong candidate for a habitable world and can potentially maintain temperate surface conditions under a wide variety of atmospheric compositions. Unfortunately, the spectral feature depths from the resulting transmission spectra and the peak flux and variations from our synthesized phase curves for TOI-700 d do not exceed 10 ppm. This will likely prohibit the James Webb Space Telescope from characterizing its atmosphere; however, this motivates the community to invest in future instrumentation that perhaps can one day reveal the true nature of TOI-700 d and to continue to search for similar planets around less distant stars.
Exploring the Atmospheric Dynamics of the Extreme Ultrahot Jupiter KELT-9b Using TESS PhotometryWong, IanShporer, AviKitzmann, DanielMorris, Brett M.Heng, KevinHoeijmakers, H. JensDemory, Brice-OlivierAhlers, John P.Mansfield, MeganBean, Jacob L.Daylan, TansuFetherolf, TaraRodriguez, Joseph E.Benneke, BjörnRicker, George R.Latham, David W.Vanderspek, RolandSeager, SaraWinn, Joshua N.Jenkins, Jon M.Burke, Christopher J.Christiansen, Jessie L.Essack, ZahraRose, Mark E.Smith, Jeffrey C.Tenenbaum, PeterYahalomi, DanielDOI: info:10.3847/1538-3881/aba2cbv. 16088
Wong, Ian, Shporer, Avi, Kitzmann, Daniel, Morris, Brett M., Heng, Kevin, Hoeijmakers, H. Jens, Demory, Brice-Olivier, Ahlers, John P., Mansfield, Megan, Bean, Jacob L., Daylan, Tansu, Fetherolf, Tara, Rodriguez, Joseph E., Benneke, Björn, Ricker, George R., Latham, David W., Vanderspek, Roland, Seager, Sara, Winn, Joshua N., Jenkins, Jon M., Burke, Christopher J., Christiansen, Jessie L., Essack, Zahra, Rose, Mark E., Smith, Jeffrey C. et al. 2020. "Exploring the Atmospheric Dynamics of the Extreme Ultrahot Jupiter KELT-9b Using TESS Photometry." The Astronomical Journal 160:88. https://doi.org/10.3847/1538-3881/aba2cb
ID: 157616
Type: article
Authors: Wong, Ian; Shporer, Avi; Kitzmann, Daniel; Morris, Brett M.; Heng, Kevin; Hoeijmakers, H. Jens; Demory, Brice-Olivier; Ahlers, John P.; Mansfield, Megan; Bean, Jacob L.; Daylan, Tansu; Fetherolf, Tara; Rodriguez, Joseph E.; Benneke, Björn; Ricker, George R.; Latham, David W.; Vanderspek, Roland; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Burke, Christopher J.; Christiansen, Jessie L.; Essack, Zahra; Rose, Mark E.; Smith, Jeffrey C.; Tenenbaum, Peter; Yahalomi, Daniel
Abstract: We carry out a phase-curve analysis of the KELT-9 system using photometric observations from NASA's Transiting Exoplanet Survey Satellite (TESS). The measured secondary eclipse depth and peak-to-peak atmospheric brightness modulation are ${650}_{-15}^{+14}$ and 566 ± 16 ppm, respectively. The planet's brightness variation reaches maximum 31 ± 5 minutes before the midpoint of the secondary eclipse, indicating a 5°2 ± 0°9 eastward shift in the dayside hot spot from the substellar point. We also detect stellar pulsations on KELT-9 with a period of 7.58695 ± 0.00091 hr. The dayside emission of KELT-9b in the TESS bandpass is consistent with a blackbody brightness temperature of 4600 ± 100 K. The corresponding nightside brightness temperature is 3040 ± 100 K, comparable to the dayside temperatures of the hottest known exoplanets. In addition, we detect a significant phase-curve signal at the first harmonic of the orbital frequency and a marginal signal at the second harmonic. While the amplitude of the first harmonic component is consistent with the predicted ellipsoidal distortion modulation assuming equilibrium tides, the phase of this photometric variation is shifted relative to the expectation. Placing KELT-9b in the context of other exoplanets with phase-curve observations, we find that the elevated nightside temperature and relatively low day-night temperature contrast agree with the predictions of atmospheric models that include H2 dissociation and recombination. The nightside temperature of KELT-9b implies an atmospheric composition containing about 50% molecular and 50% atomic hydrogen at 0.1 bar, a nightside emission spectrum that deviates significantly from a blackbody, and a 0.5-2.0 μm transmission spectrum that is featureless at low resolution.
KELT-9 b's Asymmetric TESS Transit Caused by Rapid Stellar Rotation and Spin-Orbit MisalignmentAhlers, John P.Johnson, Marshall C.Stassun, Keivan G.Colón, Knicole D.Barnes, Jason W.Stevens, Daniel J.Beatty, ThomasGaudi, B. ScottCollins, Karen A.Rodriguez, Joseph E.Ricker, GeorgeVanderspek, RolandLatham, DavidSeager, SaraWinn, JoshuaJenkins, Jon M.Caldwell, Douglas A.Goeke, Robert F.Osborn, Hugh P.Paegert, MartinRowden, PamTenenbaum, PeterDOI: info:10.3847/1538-3881/ab8fa3v. 1604
Ahlers, John P., Johnson, Marshall C., Stassun, Keivan G., Colón, Knicole D., Barnes, Jason W., Stevens, Daniel J., Beatty, Thomas, Gaudi, B. Scott, Collins, Karen A., Rodriguez, Joseph E., Ricker, George, Vanderspek, Roland, Latham, David, Seager, Sara, Winn, Joshua, Jenkins, Jon M., Caldwell, Douglas A., Goeke, Robert F., Osborn, Hugh P., Paegert, Martin, Rowden, Pam, and Tenenbaum, Peter. 2020. "KELT-9 b's Asymmetric TESS Transit Caused by Rapid Stellar Rotation and Spin-Orbit Misalignment." The Astronomical Journal 160:4. https://doi.org/10.3847/1538-3881/ab8fa3
ID: 157618
Type: article
Authors: Ahlers, John P.; Johnson, Marshall C.; Stassun, Keivan G.; Colón, Knicole D.; Barnes, Jason W.; Stevens, Daniel J.; Beatty, Thomas; Gaudi, B. Scott; Collins, Karen A.; Rodriguez, Joseph E.; Ricker, George; Vanderspek, Roland; Latham, David; Seager, Sara; Winn, Joshua; Jenkins, Jon M.; Caldwell, Douglas A.; Goeke, Robert F.; Osborn, Hugh P.; Paegert, Martin; Rowden, Pam; Tenenbaum, Peter
Abstract: KELT-9 b is an ultra-hot Jupiter transiting a rapidly rotating, oblate early-A-type star in a polar orbit. We model the effect of rapid stellar rotation on KELT-9 b's transit light curve using photometry from the Transiting Exoplanet Survey Satellite to constrain the planet's true spin-orbit angle and to explore how KELT-9 b may be influenced by stellar gravity darkening. We constrain the host star's equatorial radius to be 1.089 ± 0.017 times as large as its polar radius and its local surface brightness to vary by ∼38% between its hot poles and cooler equator. We model the stellar oblateness and surface brightness gradient and find that it causes the transit light curve to lack the usual symmetry around the time of minimum light. We take advantage of the light-curve asymmetry to constrain KELT-9 b's true spin-orbit angle ( ${87^\circ }_{{-11}^{^\circ }}^{{+10}^{^\circ }}$ ), agreeing with Gaudi et al. that KELT-9 b is in a nearly polar orbit. We also apply a gravity-darkening correction to the spectral energy distribution model from Gaudi et al. and find that accounting for rapid rotation gives a better fit to available spectroscopy and yields a more reliable estimate for the star's polar effective temperature.