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Showing 1-20 of about 49 results.
Dust entrainment in galactic windsKannan, RahulVogelsberger, M.Marinacci, F.Sales, L., V.Torrey, P.Hernquist, L.DOI: info:10.1093/mnras/stab416v. 503No. 1336–343
Kannan, Rahul, Vogelsberger, M., Marinacci, F., Sales, L., V., Torrey, P., and Hernquist, L. 2021. "Dust entrainment in galactic winds." Monthly Notices of the Royal Astronomical Society 503 (1):336– 343.
ID: 159530
Type: article
Authors: Kannan, Rahul; Vogelsberger, M.; Marinacci, F.; Sales, L., V.; Torrey, P.; Hernquist, L.
Abstract: Winds driven by stellar feedback are an essential part of the galactic ecosystem and are the main mechanism through which low-mass galaxies regulate their star formation. These winds are generally observed to be multiphase with detections of entrained neutral and molecular gas. They are also thought to enrich the circumgalactic medium around galaxies with metals and dust. This ejected dust encodes information about the integrated star formation and outflow history of the galaxy. Therefore it is important to understand how much dust is entrained and driven out of the disc by galactic winds. Here, we demonstrate that stellar feedback is efficient in driving dust-enriched winds and eject enough material to account for the amount of extraplanar dust observed in nearby galaxies. The amount of ejected dust depends on the sites from where they are launched, with dustier galaxies launching more dust-enriched outflows. Moreover, the outflowing cold and dense gas is significantly more dust enriched than the volume filling hot and tenuous material. These results provide an important new insight into the dynamics, structure, and composition of galactic winds and their role in determining the dust content of the extragalactic gas in galaxies.
Molecular hydrogen in IllustrisTNG galaxies: carefully comparing signatures of environment with local CO and SFR dataStevens, Adam R. H.Lagos, Claudia del P.Cortese, LucaCatinella, BarbaraDiemer, BenediktNelson, DylanPillepich, AnnalisaHernquist, LarsMarinacci, FedericoVogelsberger, MarkDOI: info:10.1093/mnras/staa3662v. 5023158–3178
Stevens, Adam R. H., Lagos, Claudia del P., Cortese, Luca, Catinella, Barbara, Diemer, Benedikt, Nelson, Dylan, Pillepich, Annalisa, Hernquist, Lars, Marinacci, Federico, and Vogelsberger, Mark. 2021. "Molecular hydrogen in IllustrisTNG galaxies: carefully comparing signatures of environment with local CO and SFR data." Monthly Notices of the Royal Astronomical Society 502:3158– 3178.
ID: 159273
Type: article
Authors: Stevens, Adam R. H.; Lagos, Claudia del P.; Cortese, Luca; Catinella, Barbara; Diemer, Benedikt; Nelson, Dylan; Pillepich, Annalisa; Hernquist, Lars; Marinacci, Federico; Vogelsberger, Mark
Abstract: We examine how the post-processed content of molecular hydrogen (H2) in galaxies from the TNG100 cosmological, hydrodynamic simulation changes with environment at z = 0, assessing central/satellite status and host halo mass. We make close comparisons with the carbon monoxide (CO) emission survey xCOLD GASS where possible, having mock-observed TNG100 galaxies to match the survey's specifications. For a representative sample of host haloes across 1011 ≲ M200c/M 14.6, TNG100 predicts that satellites with $m_* \ge 10^9\, {\rm M}_{\odot }$ should have a median deficit in their H2 fractions of ∼0.6 dex relative to centrals of the same stellar mass. Once observational and group-finding uncertainties are accounted for, the signature of this deficit decreases to ∼0.2 dex. Remarkably, we calculate a deficit in xCOLD GASS satellites' H2 content relative to centrals of 0.2-0.3 dex, in line with our prediction. We further show that TNG100 and SDSS data exhibit continuous declines in the average star formation rates of galaxies at fixed stellar mass in denser environments, in quantitative agreement with each other. By tracking satellites from their moment of infall in TNG100, we directly show that atomic hydrogen (H I) is depleted at fractionally higher rates than H2 on average. Supporting this picture, we find that the H2/H I mass ratios of satellites are elevated relative to centrals in xCOLD GASS. We provide additional predictions for the effect of environment on H2 - both absolute and relative to H I - that can be tested with spectral stacking in future CO surveys.
Galaxy interactions in IllustrisTNG-100, I: The power and limitations of visual identificationBlumenthal, Kelly A.Moreno, JorgeBarnes, Joshua E.Hernquist, LarsTorrey, PaulClaytor, ZacharyRodriguez-Gomez, VicenteMarinacci, FedericoVogelsberger, MarkDOI: info:10.1093/mnras/stz3472v. 4922075–2094
Blumenthal, Kelly A., Moreno, Jorge, Barnes, Joshua E., Hernquist, Lars, Torrey, Paul, Claytor, Zachary, Rodriguez-Gomez, Vicente, Marinacci, Federico, and Vogelsberger, Mark. 2020. "Galaxy interactions in IllustrisTNG-100, I: The power and limitations of visual identification." Monthly Notices of the Royal Astronomical Society 492:2075– 2094.
ID: 158035
Type: article
Authors: Blumenthal, Kelly A.; Moreno, Jorge; Barnes, Joshua E.; Hernquist, Lars; Torrey, Paul; Claytor, Zachary; Rodriguez-Gomez, Vicente; Marinacci, Federico; Vogelsberger, Mark
Abstract: We present a sample of 446 galaxy pairs constructed using the cosmological simulation IllustrisTNG-100 at z = 0, with M_FoF,dm = 10^{11}-10^{13.5} M. We produce ideal mock SDSS g-band images of all pairs to test the reliability of visual classification schema employed to produce samples of interacting galaxies. We visually classify each image as interacting or not based on the presence of a close neighbour, the presence of stellar debris fields, disturbed discs, and/or tidal features. By inspecting the trajectories of the pairs, we determine that these indicators correctly identify interacting galaxies ∼45 per cent of the time. We subsequently split the sample into the visually identified interacting pairs (VIP; 38 pairs) and those which are interacting but are not visually identified (nonVIP; 47 pairs). We find that VIP have undergone a close passage nearly twice as recently as the non-VIP, and typically have higher stellar masses. Further, the VIP sit in dark matter haloes that are approximately 2.5 times as massive, in environments nearly 2 times as dense, and are almost a factor of 10 more affected by the tidal forces of their surroundings than the nonVIP. These factors conspire to increase the observability of tidal features and disturbed morphologies, making the VIP more likely to be identified. Thus, merger rate calculations which rely on stellar morphologies are likely to be significantly biased toward massive galaxy pairs which have recently undergone a close passage.
The diversity and variability of star formation histories in models of galaxy evolutionIyer, Kartheik G.Tacchella, SandroGenel, ShyHayward, Christopher C.Hernquist, LarsBrooks, Alyson M.Caplar, NevenDavé, RomeelDiemer, BenediktForbes, John C.Gawiser, EricSomerville, Rachel S.Starkenburg, Tjitske K.DOI: info:10.1093/mnras/staa2150v. 498430–463
Iyer, Kartheik G., Tacchella, Sandro, Genel, Shy, Hayward, Christopher C., Hernquist, Lars, Brooks, Alyson M., Caplar, Neven, Davé, Romeel, Diemer, Benedikt, Forbes, John C., Gawiser, Eric, Somerville, Rachel S., and Starkenburg, Tjitske K. 2020. "The diversity and variability of star formation histories in models of galaxy evolution." Monthly Notices of the Royal Astronomical Society 498:430– 463.
ID: 158032
Type: article
Authors: Iyer, Kartheik G.; Tacchella, Sandro; Genel, Shy; Hayward, Christopher C.; Hernquist, Lars; Brooks, Alyson M.; Caplar, Neven; Davé, Romeel; Diemer, Benedikt; Forbes, John C.; Gawiser, Eric; Somerville, Rachel S.; Starkenburg, Tjitske K.
Abstract: Understanding the variability of galaxy star formation histories (SFHs) across a range of time-scales provides insight into the underlying physical processes that regulate star formation within galaxies. We compile the SFHs of galaxies at z = 0 from an extensive set of models, ranging from cosmological hydrodynamical simulations (Illustris, IllustrisTNG, Mufasa, Simba, EAGLE), zoom simulations (FIRE-2, g14, and Marvel/Justice League), semi-analytic models (Santa Cruz SAM) and empirical models (UniverseMachine), and quantify the variability of these SFHs on different time-scales using the power spectral density (PSD) formalism. We find that the PSDs are well described by broken power laws, and variability on long time-scales (≳1 Gyr) accounts for most of the power in galaxy SFHs. Most hydrodynamical models show increased variability on shorter time-scales (≲300 Myr) with decreasing stellar mass. Quenching can induce ∼0.4-1 dex of additional power on time-scales >1 Gyr. The dark matter accretion histories of galaxies have remarkably self-similar PSDs and are coherent with the in situ star formation on time-scales >3 Gyr. There is considerable diversity among the different models in their (i) power due to star formation rate variability at a given time-scale, (ii) amount of correlation with adjacent time-scales (PSD slope), (iii) evolution of median PSDs with stellar mass, and (iv) presence and locations of breaks in the PSDs. The PSD framework is a useful space to study the SFHs of galaxies since model predictions vary widely. Observational constraints in this space will help constrain the relative strengths of the physical processes responsible for this variability.
Efficacy of early stellar feedback in low gas surface density environmentsKannan, RahulMarinacci, FedericoSimpson, Christine M.Glover, Simon C. O.Hernquist, LarsDOI: info:10.1093/mnras/stz3078v. 4912088–2103
Kannan, Rahul, Marinacci, Federico, Simpson, Christine M., Glover, Simon C. O., and Hernquist, Lars. 2020. "Efficacy of early stellar feedback in low gas surface density environments." Monthly Notices of the Royal Astronomical Society 491:2088– 2103.
ID: 155675
Type: article
Authors: Kannan, Rahul; Marinacci, Federico; Simpson, Christine M.; Glover, Simon C. O.; Hernquist, Lars
Abstract: We present a suite of high-resolution radiation hydrodynamic simulations of a small patch (1 kpc2) of the interstellar medium (ISM) performed with AREPO-RT, with the aim to quantify the efficacy of various feedback processes like supernova (SN) explosions, photoheating, and radiation pressure in low gas surface density galaxies (Σgas ≃ 10 M pc-2). We show that radiative feedback decrease the star formation rate and therefore the total stellar mass formed by a factor of approximately two. This increases the gas depletion time-scale and brings the simulated Kennicutt-Schmidt relation closer to the observational estimates. Radiation feedback coupled with SN is more efficient at driving outflows with the mass and energy loading increasing by a factor of ∼10. This increase is mainly driven by the additional entrainment of medium- density (10-2 cm-3 ≤ n ≤ n -3) warm (300 K ≤ T < 8000 K) material. Therefore, including radiative feedback tends to launch colder, denser, and more mass- and energy- loaded outflows. This is because photoheating of the high-density gas around a newly formed star overpressurizes the region, causing it to expand. This reduces the ambient density in which the SN explode by a factor of 10-100 which in turn increases their momentum output by a factor of ∼1.5-2.5. Finally, we note that in these low gas surface density environments, radiative feedback primarily impact the ISM via photoheating and radiation pressure has only a minimal role in regulating star formation.
First Results from SMAUG: Characterization of Multiphase Galactic Outflows from a Suite of Local Star-forming Galactic Disk SimulationsKim, Chang-GooOstriker, Eve C.Somerville, Rachel S.Bryan, Greg L.Fielding, Drummond B.Forbes, John C.Hayward, Christopher C.Hernquist, LarsPandya, VirajDOI: info:10.3847/1538-4357/aba962v. 90061
Kim, Chang-Goo, Ostriker, Eve C., Somerville, Rachel S., Bryan, Greg L., Fielding, Drummond B., Forbes, John C., Hayward, Christopher C., Hernquist, Lars, and Pandya, Viraj. 2020. "First Results from SMAUG: Characterization of Multiphase Galactic Outflows from a Suite of Local Star-forming Galactic Disk Simulations." The Astrophysical Journal 900:61.
ID: 158031
Type: article
Authors: Kim, Chang-Goo; Ostriker, Eve C.; Somerville, Rachel S.; Bryan, Greg L.; Fielding, Drummond B.; Forbes, John C.; Hayward, Christopher C.; Hernquist, Lars; Pandya, Viraj
Abstract: Large-scale outflows in star-forming galaxies are observed to be ubiquitous and are a key aspect of theoretical modeling of galactic evolution, the focus of the Simulating Multiscale Astrophysics to Understand Galaxies (SMAUG) project. Gas blown out from galactic disks, similar to gas within galaxies, consists of multiple phases with large contrasts of density, temperature, and other properties. To study multiphase outflows as emergent phenomena, we run a suite of rougly parsec-resolution local galactic disk simulations using the TIGRESS framework. Explicit modeling of the interstellar medium (ISM), including star formation and self-consistent radiative heating plus supernova feedback, regulates ISM properties and drives the outflow. We investigate the scaling of outflow mass, momentum, energy, and metal loading factors with galactic disk properties, including star formation rate (SFR) surface density (ΣSFR ∼ 10-4 - 1 M kpc-2 yr-1), gas surface density ( ${{\rm{\Sigma }}}_{\mathrm{gas}}\sim 1\mbox{--}100\,{M}_{\odot }\,{\mathrm{pc}}^{-2}$ ), and total midplane pressure (or weight; ${P}_{\mathrm{mid}}\approx { \mathcal W }\sim {10}^{3}\mbox{--}{10}^{6}\,{k}_{B}\,{\mathrm{cm}}^{-3}\,{\rm{K}}$ ). The main components of outflowing gas are mass-delivering cool gas (T ∼ 104 K) and energy/metal-delivering hot gas (T ≳ 106 K). Cool mass outflow rates measured at outflow launch points (one or two scale heights $\sim 300\,\mathrm{pc}\mbox{--}1\,\mathrm{kpc}$ ) are 1-100 times the SFR (decreasing with ΣSFR), although in massive galaxies most mass falls back owing to insufficient outflow velocity. The hot galactic outflow carries mass comparable to 10% of the SFR, together with 10%-20% of the energy and 30%-60% of the metal mass injected by SN feedback. Importantly, our analysis demonstrates that in any physically motivated cosmological wind model it is crucial to include at least two distinct thermal wind components.
Redshift evolution of the Fundamental Plane relation in the IllustrisTNG simulationLu, ShengdongXu, DandanWang, YunchongMao, ShudeGe, JunqiangSpringel, VolkerWang, YuanVogelsberger, MarkNaiman, JillHernquist, LarsDOI: info:10.1093/mnras/staa173v. 4925930–5939
Lu, Shengdong, Xu, Dandan, Wang, Yunchong, Mao, Shude, Ge, Junqiang, Springel, Volker, Wang, Yuan, Vogelsberger, Mark, Naiman, Jill, and Hernquist, Lars. 2020. "Redshift evolution of the Fundamental Plane relation in the IllustrisTNG simulation." Monthly Notices of the Royal Astronomical Society 492:5930– 5939.
ID: 158034
Type: article
Authors: Lu, Shengdong; Xu, Dandan; Wang, Yunchong; Mao, Shude; Ge, Junqiang; Springel, Volker; Wang, Yuan; Vogelsberger, Mark; Naiman, Jill; Hernquist, Lars
Abstract: We investigate the Fundamental Plane (FP) evolution of early-type galaxies in the IllustrisTNG-100 simulation (TNG100) from redshift z = 0 to z = 2. We find that a tight plane relation already exists as early as z = 2. Its scatter stays as low as ∼0.08 dex across this redshift range. Both slope parameters b and c (where R ∝ σbIc with R, σ, and I being the typical size, velocity dispersion, and surface brightness) of the plane evolve mildly since z = 2, roughly consistent with observations. The FP residual Res (≡ a + b log σ + c log I - log R, where a is the zero-point of the FP) is found to strongly correlate with stellar age, indicating that stellar age can be used as a crucial fourth parameter of the FP. However, we find that 4c + b + 2 = δ, where δ ∼ 0.8 for FPs in TNG, rather than zero as is typically inferred from observations. This implies that a tight power-law relation between the dynamical mass-to-light ratio Mdyn/L and the dynamical mass Mdyn (where Mdyn ≡ 5σ2R/G, with G being the gravitational constant) is not present in the TNG100 simulation. Recovering such a relation requires proper mixing between dark matter and baryons, as well as star formation occurring with correct efficiencies at the right mass scales. This represents a powerful constraint on the numerical models, which has to be satisfied in future hydrodynamical simulations.
High-redshift JWST predictions from IllustrisTNG: II. Galaxy line and continuum spectral indices and dust attenuation curvesShen, XuejianVogelsberger, MarkNelson, DylanPillepich, AnnalisaTacchella, SandroMarinacci, FedericoTorrey, PaulHernquist, LarsSpringel, VolkerDOI: info:10.1093/mnras/staa1423v. 4954747–4768
Shen, Xuejian, Vogelsberger, Mark, Nelson, Dylan, Pillepich, Annalisa, Tacchella, Sandro, Marinacci, Federico, Torrey, Paul, Hernquist, Lars, and Springel, Volker. 2020. "High-redshift JWST predictions from IllustrisTNG: II. Galaxy line and continuum spectral indices and dust attenuation curves." Monthly Notices of the Royal Astronomical Society 495:4747– 4768.
ID: 156891
Type: article
Authors: Shen, Xuejian; Vogelsberger, Mark; Nelson, Dylan; Pillepich, Annalisa; Tacchella, Sandro; Marinacci, Federico; Torrey, Paul; Hernquist, Lars; Springel, Volker
Abstract: We present predictions for high redshift (z = 2-10) galaxy populations based on the IllustrisTNG simulation suite and a full Monte Carlo dust radiative transfer post-processing. Specifically, we discuss the H α and H β + $[\rm O \,{\small III}]$ luminosity functions up to z = 8. The predicted H β + $[\rm O \,{\small III}]$ luminosity functions are consistent with present observations at z ≲ 3 with ${\lesssim} 0.1\, {\rm dex}$ differences in luminosities. However, the predicted H α luminosity function is ${\sim }0.3\, {\rm dex}$ dimmer than the observed one at z ≃ 2. Furthermore, we explore continuum spectral indices, the Balmer break at 4000 Å; (D4000) and the UV continuum slope β. The median D4000 versus specific star formation rate relation predicted at z = 2 is in agreement with the local calibration despite a different distribution pattern of galaxies in this plane. In addition, we reproduce the observed AUV versus β relation and explore its dependence on galaxy stellar mass, providing an explanation for the observed complexity of this relation. We also find a deficiency in heavily attenuated, UV red galaxies in the simulations. Finally, we provide predictions for the dust attenuation curves of galaxies at z = 2-6 and investigate their dependence on galaxy colours and stellar masses. The attenuation curves are steeper in galaxies at higher redshifts, with bluer colours, or with lower stellar masses. We attribute these predicted trends to dust geometry. Overall, our results are consistent with present observations of high-redshift galaxies. Future James Webb Space Telecope observations will further test these predictions.
The Formation History of Subhalos and the Evolution of Satellite GalaxiesShi, JingjingWang, HuiyuanMo, HoujunVogelsberger, MarkHo, Luis C.Du, MinNelson, DylanPillepich, AnnalisaHernquist, LarsDOI: info:10.3847/1538-4357/ab8464v. 893139
Shi, Jingjing, Wang, Huiyuan, Mo, Houjun, Vogelsberger, Mark, Ho, Luis C., Du, Min, Nelson, Dylan, Pillepich, Annalisa, and Hernquist, Lars. 2020. "The Formation History of Subhalos and the Evolution of Satellite Galaxies." The Astrophysical Journal 893:139.
ID: 158033
Type: article
Authors: Shi, Jingjing; Wang, Huiyuan; Mo, Houjun; Vogelsberger, Mark; Ho, Luis C.; Du, Min; Nelson, Dylan; Pillepich, Annalisa; Hernquist, Lars
Abstract: Satellites constitute an important fraction of the overall galaxy population and are believed to form in dark matter subhalos. Here we use the cosmological hydrodynamic simulation TNG100 to investigate how the formation histories of subhalos affect the properties and evolution of their host galaxies. We use a scaled formation time ( ${a}_{\mathrm{nf}}$ ) to characterize the mass assembly histories of the subhalos before they are accreted by massive host halos. We find that satellite galaxies in young subhalos (low ${a}_{\mathrm{nf}}$ ) are less massive and more gas-rich and have stronger star formation and a higher fraction of ex situ stellar mass than satellites in old subhalos (high ${a}_{\mathrm{nf}}$ ). Furthermore, these low- ${a}_{\mathrm{nf}}$ satellites require longer timescales to be quenched as a population than the high- ${a}_{\mathrm{nf}}$ counterparts. We find very different merger histories between satellites in fast-accretion (FA, ${a}_{\mathrm{nf}}\lt 1.3$ ) and slow-accretion (SA, ${a}_{\mathrm{nf}}\gt 1.3$ ) subhalos. For FA satellites the galaxy merger frequency dramatically increases just after accretion, which enhances the star formation at accretion, whereas for SA satellites the mergers occur smoothly and continuously across the accretion time. Moreover, mergers with FA satellites happen mainly after accretion, while a contrary trend is found for SA satellites. Our results provide insight into the evolution and star formation quenching of the satellite population.
High-redshift JWST predictions from IllustrisTNG: dust modelling and galaxy luminosity functionsVogelsberger, MarkNelson, DylanPillepich, AnnalisaShen, XuejianMarinacci, FedericoSpringel, VolkerPakmor, RüdigerTacchella, SandroWeinberger, RainerTorrey, PaulHernquist, LarsDOI: info:10.1093/mnras/staa137v. 4925167–5201
Vogelsberger, Mark, Nelson, Dylan, Pillepich, Annalisa, Shen, Xuejian, Marinacci, Federico, Springel, Volker, Pakmor, Rüdiger, Tacchella, Sandro, Weinberger, Rainer, Torrey, Paul, and Hernquist, Lars. 2020. "High-redshift JWST predictions from IllustrisTNG: dust modelling and galaxy luminosity functions." Monthly Notices of the Royal Astronomical Society 492:5167– 5201.
ID: 156459
Type: article
Authors: Vogelsberger, Mark; Nelson, Dylan; Pillepich, Annalisa; Shen, Xuejian; Marinacci, Federico; Springel, Volker; Pakmor, Rüdiger; Tacchella, Sandro; Weinberger, Rainer; Torrey, Paul; Hernquist, Lars
Abstract: The James Webb Space Telescope (JWST) promises to revolutionize our understanding of the early Universe, and contrasting its upcoming observations with predictions of the Λ cold dark matter model requires detailed theoretical forecasts. Here, we exploit the large dynamic range of the IllustrisTNG simulation suite, TNG50, TNG100, and TNG300, to derive multiband galaxy luminosity functions from z = 2 to z = 10. We put particular emphasis on the exploration of different dust attenuation models to determine galaxy luminosity functions for the rest-frame ultraviolet (UV), and apparent wide NIRCam bands. Our most detailed dust model is based on continuum Monte Carlo radiative transfer calculations employing observationally calibrated dust properties. This calibration results in constraints on the redshift evolution of the dust attenuation normalization and dust-to-metal ratios yielding a stronger redshift evolution of the attenuation normalization compared to most previous theoretical studies. Overall we find good agreement between the rest- frame UV luminosity functions and observational data for all redshifts, also beyond the regimes used for the dust model calibrations. Furthermore, we also recover the observed high-redshift (z = 4-6) UV luminosity versus stellar mass relation, the H α versus star formation rate relation, and the H α luminosity function at z = 2. The bright end (MUV > -19.5) cumulative galaxy number densities are consistent with observational data. For the F200W NIRCam band, we predict that JWST will detect ∼80 (∼200) galaxies with a signal-to-noise ratio of 10 (5) within the NIRCam field of view, 2.2× 2.2 arcmin2, for a total exposure time of 10^5 s in the redshift range z = 8 ± 0.5. These numbers drop to ∼10 (∼40) for an exposure time of 10^4 s.
Early-type galaxy density profiles from IllustrisTNG - I. Galaxy correlations and the impact of baryonsWang, YunchongVogelsberger, MarkXu, DandanMao, ShudeSpringel, VolkerLi, HuiBarnes, DavidHernquist, LarsPillepich, AnnalisaMarinacci, FedericoPakmor, RüedigerWeinberger, RainerTorrey, PaulDOI: info:10.1093/mnras/stz3348v. 4915188–5215
Wang, Yunchong, Vogelsberger, Mark, Xu, Dandan, Mao, Shude, Springel, Volker, Li, Hui, Barnes, David, Hernquist, Lars, Pillepich, Annalisa, Marinacci, Federico, Pakmor, Rüediger, Weinberger, Rainer, and Torrey, Paul. 2020. "Early-type galaxy density profiles from IllustrisTNG - I. Galaxy correlations and the impact of baryons." Monthly Notices of the Royal Astronomical Society 491:5188– 5215.
ID: 158036
Type: article
Authors: Wang, Yunchong; Vogelsberger, Mark; Xu, Dandan; Mao, Shude; Springel, Volker; Li, Hui; Barnes, David; Hernquist, Lars; Pillepich, Annalisa; Marinacci, Federico; Pakmor, Rüediger; Weinberger, Rainer; Torrey, Paul
Abstract: We explore the isothermal total density profiles of early-type galaxies (ETGs) in the IllustrisTNG simulation. For the selected 559 ETGs at z = 0 with stellar masses 10^{10.7} M_{☉ } ≤ M_{\ast } ≤ 10^{11.9} M_{☉ }, the total power-law slope has a mean of = 2.011 ± 0.007 and a scatter of σ _{γ ^' }} = 0.171 over the radial range 0.4-4 times the stellar half-mass radius. Several correlations between γ′ and galactic properties including stellar mass, effective radius, stellar surface density, central velocity dispersion, central dark matter fraction, and in situ-formed stellar mass ratio are compared to observations and other simulations, revealing that IllustrisTNG reproduces many correlation trends, and in particular, γ′ is almost constant with redshift below z = 2. Through analysing IllustrisTNG model variations, we show that black hole kinetic winds are crucial to lowering γ′ and matching observed galaxy correlations. The effects of stellar winds on γ′ are subdominant compared to active galactic nucleus (AGN) feedback, and differ due to the presence of AGN feedback from previous works. The density profiles of the ETG dark matter haloes are well described by steeper than NFW profiles, and they are steeper in the full physics (FP) run than their counterparts in the dark matter-only (DMO) run. Their inner density slopes anticorrelate (remain constant) with the halo mass in the FP (DMO) run, and anticorrelate with the halo concentration parameter c200 in both the types of runs. The dark matter haloes of low-mass ETGs are contracted whereas high-mass ETGs are expanded, suggesting that variations in the total density profile occur through the different halo responses to baryons.
Enhancing AGN efficiency and cool-core formation with anisotropic thermal conductionBarnes, David J.Kannan, RahulVogelsberger, MarkPfrommer, ChristophPuchwein, EwaldWeinberger, RainerSpringel, VolkerPakmor, RüdigerNelson, DylanMarinacci, FedericoPillepich, AnnalisaTorrey, PaulHernquist, LarsDOI: info:10.1093/mnras/stz1814v. 4883003–3013
Barnes, David J., Kannan, Rahul, Vogelsberger, Mark, Pfrommer, Christoph, Puchwein, Ewald, Weinberger, Rainer, Springel, Volker, Pakmor, Rüdiger, Nelson, Dylan, Marinacci, Federico, Pillepich, Annalisa, Torrey, Paul, and Hernquist, Lars. 2019. "Enhancing AGN efficiency and cool-core formation with anisotropic thermal conduction." Monthly Notices of the Royal Astronomical Society 488:3003– 3013.
ID: 154419
Type: article
Authors: Barnes, David J.; Kannan, Rahul; Vogelsberger, Mark; Pfrommer, Christoph; Puchwein, Ewald; Weinberger, Rainer; Springel, Volker; Pakmor, Rüdiger; Nelson, Dylan; Marinacci, Federico; Pillepich, Annalisa; Torrey, Paul; Hernquist, Lars
Abstract: Understanding how baryonic processes shape the intracluster medium (ICM) is of critical importance to the next generation of galaxy cluster surveys. However, many models of structure formation neglect potentially important physical processes, like anisotropic thermal conduction (ATC). We explore the impact of ATC on the prevalence of cool-cores (CCs) via 12 pairs of magnetohydrodynamical galaxy cluster simulations, using the IllustrisTNG model with and without ATC. Examining their properties we find that the addition of ATC has a negligible impact on the median rotation measure, plasma β, the magnetic field-radial direction angle, and the effective Spitzer value. However, the scatter in the angle and effective Spitzer value is 50 per cent larger with ATC because the magnetic field aligns with the azimuthal direction to a greater extent in relaxed clusters. ATC's impact varies from cluster to cluster and with CC criterion, but its inclusion produces a systematic shift to larger CC fractions at z = 0 for all CC criteria considered. Additionally, the inclusion of ATC flattens the CC fraction redshift evolution, helping to ease the tension with the observed evolution. With ATC, the energy required for the central black hole to self-regulate is reduced by 24 per cent and the gas fraction at 0.01 r_{500} increases by 100 per cent, producing larger CC fractions. ATC makes the ICM unstable to perturbations and the increased efficiency of AGN feedback suggests that its inclusion results in a greater level of mixing in the ICM, demonstrated by the 10 per cent reduction in central metallicity for clusters with ATC.
Shape of dark matter haloes in the Illustris simulation: effects of baryonsChua, Kun Ting EddiePillepich, AnnalisaVogelsberger, MarkHernquist, LarsDOI: info:10.1093/mnras/sty3531v. 484No. 1476–493
Chua, Kun Ting Eddie, Pillepich, Annalisa, Vogelsberger, Mark, and Hernquist, Lars. 2019. "Shape of dark matter haloes in the Illustris simulation: effects of baryons." Monthly Notices of the Royal Astronomical Society 484 (1):476– 493.
ID: 153337
Type: article
Authors: Chua, Kun Ting Eddie; Pillepich, Annalisa; Vogelsberger, Mark; Hernquist, Lars
Atomic and molecular gas in IllustrisTNG galaxies at low redshiftDiemer, BenediktStevens, Adam R. H.Lagos, Claudia del P.Calette, A. R.Tacchella, SandroHernquist, LarsMarinacci, FedericoNelson, DylanPillepich, AnnalisaRodriguez-Gomez, VicenteVillaescusa-Navarro, FranciscoVogelsberger, MarkDOI: info:10.1093/mnras/stz1323v. 4871529–1550
Diemer, Benedikt, Stevens, Adam R. H., Lagos, Claudia del P., Calette, A. R., Tacchella, Sandro, Hernquist, Lars, Marinacci, Federico, Nelson, Dylan, Pillepich, Annalisa, Rodriguez-Gomez, Vicente, Villaescusa-Navarro, Francisco, and Vogelsberger, Mark. 2019. "Atomic and molecular gas in IllustrisTNG galaxies at low redshift." Monthly Notices of the Royal Astronomical Society 487:1529– 1550.
ID: 154280
Type: article
Authors: Diemer, Benedikt; Stevens, Adam R. H.; Lagos, Claudia del P.; Calette, A. R.; Tacchella, Sandro; Hernquist, Lars; Marinacci, Federico; Nelson, Dylan; Pillepich, Annalisa; Rodriguez-Gomez, Vicente; Villaescusa-Navarro, Francisco; Vogelsberger, Mark
Abstract: We have recently developed a post-processing framework to estimate the abundance of atomic and molecular hydrogen (H I and H2, respectively) in galaxies in large-volume cosmological simulations. Here we compare the H I and H2 content of IllustrisTNG galaxies to observations. We mostly restrict this comparison to z ≈ 0 and consider six observational metrics: the overall abundance of H I and H2, their mass functions, gas fractions as a function of stellar mass, the correlation between H2 and star formation rate, the spatial distribution of gas, and the correlation between gas content and morphology. We find generally good agreement between simulations and observations, particularly for the gas fractions and the H I mass-size relation. The H2 mass correlates with star formation rate as expected, revealing an almost constant depletion time that evolves up to z = 2 as observed. However, we also discover a number of tensions with varying degrees of significance, including an overestimate of the total neutral gas abundance at z = 0 by about a factor of 2 and a possible excess of satellites with no or very little neutral gas. These conclusions are robust to the modelling of the H I/H2 transition. In terms of their neutral gas properties, the IllustrisTNG simulations represent an enormous improvement over the original Illustris run. All data used in this paper are publicly available as part of the IllustrisTNG data release.
Extreme spheres: counts-in-cells for 21cm intensity mappingLeicht, OliverUhlemann, CoraVillaescusa-Navarro, FranciscoCodis, SandrineHernquist, LarsGenel, ShyDOI: info:10.1093/mnras/sty3469v. 484No. 1269–281
Leicht, Oliver, Uhlemann, Cora, Villaescusa-Navarro, Francisco, Codis, Sandrine, Hernquist, Lars, and Genel, Shy. 2019. "Extreme spheres: counts-in-cells for 21cm intensity mapping." Monthly Notices of the Royal Astronomical Society 484 (1):269– 281.
ID: 153335
Type: article
Authors: Leicht, Oliver; Uhlemann, Cora; Villaescusa-Navarro, Francisco; Codis, Sandrine; Hernquist, Lars; Genel, Shy
A Deep Learning Approach to Galaxy Cluster X-Ray MassesNtampaka, MichelleZuHone, J.Eisenstein, D.Nagai, D.Vikhlinin, A.Hernquist, L.Marinacci, F.Nelson, D.Pakmor, R.Pillepich, A.Torrey, P.Vogelsberger, M.DOI: info:10.3847/1538-4357/ab14ebv. 87682
Ntampaka, Michelle, ZuHone, J., Eisenstein, D., Nagai, D., Vikhlinin, A., Hernquist, L., Marinacci, F., Nelson, D., Pakmor, R., Pillepich, A., Torrey, P., and Vogelsberger, M. 2019. "A Deep Learning Approach to Galaxy Cluster X-Ray Masses." The Astrophysical Journal 876:82.
ID: 151867
Type: article
Authors: Ntampaka, Michelle; ZuHone, J.; Eisenstein, D.; Nagai, D.; Vikhlinin, A.; Hernquist, L.; Marinacci, F.; Nelson, D.; Pakmor, R.; Pillepich, A.; Torrey, P.; Vogelsberger, M.
Abstract: We present a machine-learning (ML) approach for estimating galaxy cluster masses from Chandra mock images. We utilize a Convolutional Neural Network (CNN), a deep ML tool commonly used in image recognition tasks. The CNN is trained and tested on our sample of 7896 Chandra X-ray mock observations, which are based on 329 massive clusters from the {\text{}}{IllustrisTNG} simulation. Our CNN learns from a low resolution spatial distribution of photon counts and does not use spectral information. Despite our simplifying assumption to neglect spectral information, the resulting mass values estimated by the CNN exhibit small bias in comparison to the true masses of the simulated clusters (‑0.02 dex) and reproduce the cluster masses with low intrinsic scatter, 8% in our best fold and 12% averaging over all. In contrast, a more standard core-excised luminosity method achieves 15%–18% scatter. We interpret the results with an approach inspired by Google DeepDream and find that the CNN ignores the central regions of clusters, which are known to have high scatter with mass.
The optical morphologies of galaxies in the IllustrisTNG simulation: a comparison to Pan-STARRS observationsRodriguez-Gomez, VicenteSnyder, Gregory F.Lotz, Jennifer M.Nelson, DylanPillepich, AnnalisaSpringel, VolkerGenel, ShyWeinberger, RainerTacchella, SandroPakmor, RüdigerTorrey, PaulMarinacci, FedericoVogelsberger, MarkHernquist, LarsThilker, David A.DOI: info:10.1093/mnras/sty3345v. 4834140–4159
Rodriguez-Gomez, Vicente, Snyder, Gregory F., Lotz, Jennifer M., Nelson, Dylan, Pillepich, Annalisa, Springel, Volker, Genel, Shy, Weinberger, Rainer, Tacchella, Sandro, Pakmor, Rüdiger, Torrey, Paul, Marinacci, Federico, Vogelsberger, Mark, Hernquist, Lars, and Thilker, David A. 2019. "The optical morphologies of galaxies in the IllustrisTNG simulation: a comparison to Pan-STARRS observations." Monthly Notices of the Royal Astronomical Society 483:4140– 4159.
ID: 150915
Type: article
Authors: Rodriguez-Gomez, Vicente; Snyder, Gregory F.; Lotz, Jennifer M.; Nelson, Dylan; Pillepich, Annalisa; Springel, Volker; Genel, Shy; Weinberger, Rainer; Tacchella, Sandro; Pakmor, Rüdiger; Torrey, Paul; Marinacci, Federico; Vogelsberger, Mark; Hernquist, Lars; Thilker, David A.
Abstract: We have generated synthetic images of ˜27 000 galaxies from the IllustrisTNG and the original Illustris hydrodynamic cosmological simulations, designed to match Pan-STARRS observations of log10(M*/M) ≈ 9.8-11.3 galaxies at z ≈ 0.05. Most of our synthetic images were created with the SKIRT radiative transfer code, including the effects of dust attenuation and scattering, and performing the radiative transfer directly on the Voronoi mesh used by the simulations themselves. We have analysed both our synthetic and real Pan-STARRS images with the newly developed statmorph code, which calculates non-parametric morphological diagnostics - including the Gini-M20 and concentration-asymmetry-smoothness statistics - and performs 2D Sérsic fits. Overall, we find that the optical morphologies of IllustrisTNG galaxies are in good agreement with observations, and represent a substantial improvement compared to the original Illustris simulation. In particular, the locus of the Gini-M20 diagram is consistent with that inferred from observations, while the median trends with stellar mass of all the morphological, size and shape parameters considered in this work lie within the ˜1σ scatter of the observational trends. However, the IllustrisTNG model has some difficulty with more stringent tests, such as producing a strong morphology-colour relation. This results in a somewhat higher fraction of red discs and blue spheroids compared to observations. Similarly, the morphology-size relation is problematic: while observations show that discs tend to be larger than spheroids at a fixed stellar mass, such a trend is not present in IllustrisTNG.
Atomic hydrogen in IllustrisTNG galaxies: the impact of environment parallelled with local 21-cm surveysStevens, Adam R. H.Diemer, BenediktLagos, Claudia del P.Nelson, DylanPillepich, AnnalisaBrown, TobyCatinella, BarbaraHernquist, LarsWeinberger, RainerVogelsberger, MarkMarinacci, FedericoDOI: info:10.1093/mnras/sty3451v. 483No. 45334–5354
Stevens, Adam R. H., Diemer, Benedikt, Lagos, Claudia del P., Nelson, Dylan, Pillepich, Annalisa, Brown, Toby, Catinella, Barbara, Hernquist, Lars, Weinberger, Rainer, Vogelsberger, Mark, and Marinacci, Federico. 2019. "Atomic hydrogen in IllustrisTNG galaxies: the impact of environment parallelled with local 21-cm surveys." Monthly Notices of the Royal Astronomical Society 483 (4):5334– 5354.
ID: 153332
Type: article
Authors: Stevens, Adam R. H.; Diemer, Benedikt; Lagos, Claudia del P.; Nelson, Dylan; Pillepich, Annalisa; Brown, Toby; Catinella, Barbara; Hernquist, Lars; Weinberger, Rainer; Vogelsberger, Mark; Marinacci, Federico
Zooming in on accretion – II. Cold circumgalactic gas simulated with a super-Lagrangian refinement schemeSuresh, JoshuaNelson, DylanGenel, ShyRubin, Kate H. R.Hernquist, LarsDOI: info:10.1093/mnras/sty3402v. 483No. 34040–4059
Suresh, Joshua, Nelson, Dylan, Genel, Shy, Rubin, Kate H. R., and Hernquist, Lars. 2019. "Zooming in on accretion – II. Cold circumgalactic gas simulated with a super-Lagrangian refinement scheme." Monthly Notices of the Royal Astronomical Society 483 (3):4040– 4059.
ID: 153331
Type: article
Authors: Suresh, Joshua; Nelson, Dylan; Genel, Shy; Rubin, Kate H. R.; Hernquist, Lars
Morphology and star formation in IllustrisTNG: the build-up of spheroids and discsTacchella, SandroDiemer, BenediktHernquist, LarsGenel, ShyMarinacci, FedericoNelson, DylanPillepich, AnnalisaRodriguez-Gomez, VicenteSales, Laura V.Springel, VolkerVogelsberger, MarkDOI: info:10.1093/mnras/stz1657v. 4875416–5440
Tacchella, Sandro, Diemer, Benedikt, Hernquist, Lars, Genel, Shy, Marinacci, Federico, Nelson, Dylan, Pillepich, Annalisa, Rodriguez-Gomez, Vicente, Sales, Laura V., Springel, Volker, and Vogelsberger, Mark. 2019. "Morphology and star formation in IllustrisTNG: the build-up of spheroids and discs." Monthly Notices of the Royal Astronomical Society 487:5416– 5440.
ID: 154283
Type: article
Authors: Tacchella, Sandro; Diemer, Benedikt; Hernquist, Lars; Genel, Shy; Marinacci, Federico; Nelson, Dylan; Pillepich, Annalisa; Rodriguez-Gomez, Vicente; Sales, Laura V.; Springel, Volker; Vogelsberger, Mark
Abstract: Using the IllustrisTNG simulations, we investigate the connection between galaxy morphology and star formation in central galaxies with stellar masses in the range 109-1011.5 M. We quantify galaxy morphology by a kinematical decomposition of the stellar component into a spheroidal and a disc component (spheroid-to-total ratio, S/T) and by the concentration of the stellar mass density profile (C82). S/T is correlated with stellar mass and star formation activity, while C82 correlates only with stellar mass. Overall, we find good agreement with observational estimates for both S/T and C82. Low- and high- mass galaxies are dominated by random stellar motion, while only intermediate-mass galaxies (M ≈ 1010-1010.5 M) are dominated by ordered rotation. Whereas higher mass galaxies are typical spheroids with high concentrations, lower mass galaxies have low concentration, pointing to different formation channels. Although we find a correlation between S/T and star formation activity, in the TNG model galaxies do not necessarily change their morphology when they transition through the green valley or when they cease their star formation, this depending on galaxy stellar mass and morphological estimator. Instead, the morphology (S/T and C82) is generally set during the star-forming phase of galaxies. The apparent correlation between S/T and star formation arises because earlier forming galaxies had, on average, a higher S/T at a given stellar mass. Furthermore, we show that mergers drive in situ bulge formation in intermediate-mass galaxies and are responsible for the recent spheroidal mass assembly in the massive galaxies with M > 1011 M. In particular, these massive galaxies assemble about half of the spheroidal mass while star- forming and the other half through mergers while quiescent.