Abstract
We examine galaxy star formation rates (SFRs), metallicities and gas
contents predicted by the Mufasa cosmological hydrodynamic simulations,
which employ meshless hydrodynamics and novel feedback prescriptions
that yield a good match to observed galaxy stellar mass assembly. We
combine 50, 25 and 12.5 h-1 Mpc boxes with a quarter billion
particles each to show that Mufasa broadly reproduces a wide range of
relevant observations, including SFR and specific SFR functions, the
mass-metallicity relation, H I and H2 fractions, H I (21 cm)
and CO luminosity functions, and cosmic gas density evolution. There are
mild but significant discrepancies, such as perhaps too many high-SFR
galaxies, overly metal-rich and H I-poor galaxies at M*
≳ 2 × 1010 M⊙, and specific star
formation rates that are too low at z ˜ 1-2. The H I mass function
increases by ×2 out to z ˜ 1, then steepens to higher
redshifts, while the CO luminosity function computed using the Narayanan
et al. conversion factor shows a rapid increase of CO-bright galaxies
out to z ˜ 2 in accord with data. Ω _{H I} and
ΩH2 both scale roughly as ∝(1 + z)0.7
out to z ˜ 3, comparable to the rise in H I and H2
fractions. Mufasa galaxies with high SFR at a given M* have
lower metallicities and higher H I and H2 fractions,
following observed trends; we make quantitative predictions for how the
fluctuations in the baryon cycle drive correlated scatter around galaxy
scaling relations. Most of these trends are well converged with
numerical resolution. These successes highlight Mufasa as a viable
platform to study many facets of cosmological galaxy evolution.
Original language | English |
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Pages (from-to) | 115-132 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 467 |
Issue number | 1 |
DOIs | |
Publication status | Published - 15 Jan 2017 |
Keywords / Materials (for Non-textual outputs)
- galaxies: formation
- galaxies: evolution
- galaxies: star formation
- galaxies: abundances
- galaxies: ISM
- methods: numerical