Introducing the Illustris Project: the evolution of galaxy populations across cosmic time

By Shy Genel, M. Vogelsberger, Volker Springel, D. Sijacki, D. Nelson, Gregory F. Snyder, V. Rodriguez-Gomez, P. Torrey, L. Hernquist. 2014

741 citations recorded by the source corpus.

We present an overview of galaxy evolution across cosmic time in the Illustris Simulation. Illustris is an N-body/hydrodynamical simulation that evolves 2*1820^3 resolution elements in a (106.5Mpc)^3 box from cosmological initial conditions down to z=0 using the AREPO moving-mesh code. The simulation uses a state-of-the-art set of physical models for galaxy formation that was tuned to reproduce the z=0 stellar mass function and the history of the cosmic star-formation rate density. We find that Illustris successfully reproduces a plethora of observations of galaxy populations at various redshifts, for which no tuning was performed, and provide predictions for future observations. In particular, we discuss (a) the buildup of galactic mass, showing stellar mass functions and the relations between stellar mass and halo mass from z=7 to z=0, (b) galaxy number density profiles around massive central galaxies out to z=4, (c) the gas and total baryon content of both galaxies and their halos for different redshifts, and as a function of mass and radius, and (d) the evolution of galaxy specific star-formation rates up to z=8. In addition, we (i) present a qualitative analysis of galaxy morphologies from z=5 to z=0, for the stellar as well as the gaseous components, and their appearance in HST mock observations, (ii) follow galaxies selected at z=2 to their z=0 descendants, and quantify their growth and merger histories, and (iii) track massive z=0 galaxies to high redshift and study their joint evolution in star-formation activity and compactness. We conclude with a discussion of several disagreements with observations, and lay out possible directions for future research.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/e25a37517bf695c5c17e8e29c2fe970e619ad869

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In Astronomy and Astrophysics

1. P. Hopkins
2. L. Hernquist
3. Volker Springel
4. R. Dav'e
5. R. Somerville
6. T. Naab
7. A. Dekel
8. D. Keres̆

In Instrumentation

1. P. Hopkins
2. L. Hernquist
3. Volker Springel
4. R. Dav'e
5. R. Somerville
6. A. Dekel
7. T. Naab
8. C. Conroy

Citations in the corpus

• Colours and luminosities of z = 0.1 galaxies in the eagle simulation (2015, methodology): “…take τ̂ism and τ̂bc to be constants, τ̂bc = 0.67 τ̂ism = 0.33, (3) with λv = 5500 Å and tdisp = 107 yr, which were calibrated to fit starburst galaxies and were used for the recent analysis of the ILLUSTRIS simulations (Vogelsberger et al. 2014) by Genel et al. (2014) and Torrey et al. (2015).”
• The COSMOS2015 galaxy stellar mass function . Thirteen billion years of stellar mass assembly in ten snapshots (2017, methodology): “…and hydrodynamical simulations are often (but not always, see e.g. Dubois et al. 2014) calibrated against the local SMF (e.g. Guo et al. 2011, 2013; Genel et al. 2014; Schaye et al. 2016); measurements at z > 0 are then used to test theoretical predictions (Torrey et al. 2014; Furlong et al. 2015,…”
• The size evolution of star-forming and quenched galaxies in the IllustrisTNG simulation (2017, background): “This represents a mild improvement upon the original Illustris simulation, where the slope was at most −0.08 (Genel et al. 2014).”
• xCOLD GASS: The Complete IRAM 30 m Legacy Survey of Molecular Gas for Galaxy Evolution Studies (2017, background): “…(e.g. Combes et al. 2013; Troncoso et al. 2014; Seko et al. 2016; Genzel et al. 2015; Tacconi et al. 2017), and provides powerful constraints for theoretical models and numerical simulations (e.g. Lagos et al. 2011; Genel et al. 2014; Popping et al. 2015; Lagos et al. 2015; Davé et al. 2017).”
• Dwarf galaxies in CDM and SIDM with baryons: observational probes of the nature of dark matter (2014, methodology): “Recently, this model was also employed to run the Illustris simulation (see Genel et al. 2014; Vogelsberger et al. 2014a,b, for more details).”
• The Horizon-AGN simulation: evolution of galaxy properties over cosmic time (2016, methodology): “…redshift range studied here, most simulations that are similar to HorizonAGN produce reasonably good agreement with data (e.g. Furlong et al. 2015; Genel et al. 2014; Khandai et al. 2015), although a detailed comparison between models is difficult, because all models are typically not compared to…”
• First results from the IllustrisTNG simulations: radio haloes and magnetic fields (2017, methodology): “The IllustrisTNG1 simulation series is the follow-up project of the Illustris simulation suite (Vogelsberger et al. 2014a,b; Genel et al. 2014; Nelson et al. 2015; Sijacki et al. 2015).”
• Molecular hydrogen abundances of galaxies in the EAGLE simulations (2015, methodology): “Genel et al. (2014) presented molecular gas scaling relations for the Illustris simulation, and showed that it reproduces the observed correlation between H2 and stellar mass reasonably well if the starforming gas (which has high enough density to allow star formation to take place) is used as a…”
• THE EVOLUTION OF THE GALAXY STELLAR MASS FUNCTION AT z = 4–8: A STEEPENING LOW-MASS-END SLOPE WITH INCREASING REDSHIFT (2015, background): “The simulation with a dark matter mass resolution of 6.26×106 M was run in a box ∼(100 Mpc)3 and was tuned to reproduce the observed GSMF at z ∼ 0 and the evolution of the cosmic SFRD. Figure 14 shows that the predictions from Illustris are consistent with our observations at all masses at z = 6–7 a”
• simba: Cosmological simulations with black hole growth and feedback (2019, methodology): “Modern cosmological-scale simulations such as Illustris (Vogelsberger et al. 2014; Genel et al. 2014), Magneticum (Hirschmann et al. 2014), Horizon-AGN (Dubois et al. 2014; Volonteri et al. 2016; Kaviraj et al. 2017), Eagle (Schaye et al. 2015), MassiveBlack (Khandai et al. 2015), Blue Tides (Feng…”
• CONSTRAINING THE LOW-MASS SLOPE OF THE STAR FORMATION SEQUENCE AT 0.5 < z < 2.5 (2014, background): “For example, the normalization of the SFRs is ∼0.3 dex higher than predicted from the growth of the mass function at 1 < z < 2.5 (Leja et al. 2014; see also Genel et al. 2014).”
• Neutral hydrogen in galaxy haloes at the peak of the cosmic star formation history (2014, result): “…large-volume simulations (Vogelsberger et al. 2014; Schaye et al. 2015) with parameterized feedback models also contain for the first time a mixture of spiral and elliptical galaxies in qualitative agreement with observations (but with significant quantitative discrepancies; Genel et al. 2014).”
• Supermassive black holes and their feedback effects in the IllustrisTNG simulation (2017, background): “…galaxies have significantly improved stellar (Nelson et al. 2017; Pillepich et al. 2017a; Genel et al. 2017) and gas properties (Vogelsberger et al. 2017; Marinacci et al. 2017; Weinberger et al. 2017) compared to the predecessor Illustris simulation (Vogelsberger et al. 2014; Genel et al. 2014).”
• Deriving Physical Properties from Broadband Photometry with Prospector: Description of the Model and a Demonstration of its Accuracy Using 129 Galaxies in the Local Universe (2016, background): “Hydrodynamical simulations (e.g., Genel et al. 2014; Torrey et al. 2014; Furlong et al. 2015), semi-analytical models (e.g., Mitchell et al. 2014; Henriques et al. 2015), and pure analytic models (e.g., Lilly et al. 2013; Dekel & Burkert 2014) are all systematically offset from observations of…”
• The Auriga Project: the properties and formation mechanisms of disc galaxies across cosmic time (2016, background): “…including BH accretion and feedback, stellar feedback, stellar evolution, chemical evolution, metallicitydependent cooling, star formation and magnetic fields, and has been shown to produce realistic galaxy populations in large-scale cosmological boxes (Vogelsberger et al. 2013; Genel et al. 2014).”
• First results from the TNG50 simulation: galactic outflows driven by supernovae and black hole feedback (2019, background): “…clarified the need for efficient outflows in order to make realistic galaxy populations whose characteristics and integral properties are roughly in agreement with observational constraints (Vogelsberger et al. 2014; Genel et al. 2014; Crain et al. 2015; Schaye et al. 2015; Dubois et al. 2016).”
• The optical morphologies of galaxies in the IllustrisTNG simulation: a comparison to Pan-STARRS observations (2018, methodology): “We also use data from the original Illustris simulation (Vogelsberger et al. 2014a,b; Genel et al. 2014; Sijacki et al. 2015; Nelson et al. 2015), which follows the evolution of 2 × 18203 resolution elements within a periodic cube measuring 75h−1 ≈ 106.5 Mpc per side, with a baryonic mass…”
• The MassiveBlack-II simulation: The evolution of haloes and galaxies to z ~ 0 (2014, methodology): “However these simulations, still small in volume, miss out on massive haloes but when scaled to larger volumes of Lbox = 75 Mpc h−1, e.g. in the Illustris simulation (Genel et al. 2014; Vogelsberger et al. 2014a,b), the GSMF is still overpredicted at large masses at z = 0.”