2014/05/31 by Mark Vogelsberger, Shy Genel, Volker Springel +6 · 1 citation
Physics and Astronomy · #astro-ph.CO
paper · pdf · doi:10.1093/mnras/stu1536
32 pages, 26 figures. MNRAS accepted. The official Illustris website can be found at http://www.illustris-project.org
arxiv created 2014/09/20 · arxiv updated 2015/06/19
We introduce the Illustris Project, a series of large-scale hydrodynamical simulations of galaxy formation. The highest resolution simulation, Illustris-1, covers a volume of (106.5 \rm Mpc)3, has a dark mass resolution of 6.26 × 106 \rm M_\odot, and an initial baryonic matter mass resolution of 1.26 × 106 \rm M_\odot. At z=0 gravitational forces are softened on scales of 710 \rm pc, and the smallest hydrodynamical gas cells have an extent of 48 \rm pc. We follow the dynamical evolution of 2× 18203 resolution elements and in addition passively evolve 18203 Monte Carlo tracer particles reaching a total particle count of more than 18 billion. The galaxy formation model includes: primordial and metal-line cooling with self-shielding corrections, stellar evolution, stellar feedback, gas recycling, chemical enrichment, supermassive black hole growth, and feedback from active galactic nuclei. At z=0 our simulation volume contains about 40,000 well-resolved galaxies covering a diverse range of morphologies and colours including early-type, late-type and irregular galaxies. The simulation reproduces reasonably well the cosmic star formation rate density, the galaxy luminosity function, and baryon conversion efficiency at z=0. It also qualitatively captures the impact of galaxy environment on the red fractions of galaxies. The internal velocity structure of selected well-resolved disk galaxies obeys the stellar and baryonic Tully-Fisher relation together with flat circular velocity curves. In the well-resolved regime the simulation reproduces the observed mix of early-type and late-type galaxies. Our model predicts a halo mass dependent impact of baryonic effects on the halo mass function and the masses of haloes caused by feedback from supernova and active galactic nuclei.