Constraining the galaxy-halo connection over the last 13.3 Gyr: star formation histories, galaxy mergers and structural properties
Abstract
We present new determinations of the stellar-to-halo mass relation (SHMR) at z = 0-10 that match the evolution of the galaxy stellar mass function, the star formation rate (SFR)-M* relation and the cosmic SFR. We utilize a compilation of 40 observational studies from the literature and correct them for potential biases. Using our robust determinations of halo mass assembly and the SHMR, we infer star formation histories, merger rates and structural properties for average galaxies, combining star-forming and quenched galaxies. Our main findings are as follows: (1) The halo mass M50 above which 50 per cent of galaxies are quenched coincides with sSFR/sMAR ∼ 1, where sSFR is the specific SFR and sMAR is the specific halo mass accretion rate. (2) M50 increases with redshift, presumably due to cold streams being more efficient at high redshifts, while virial shocks and active galactic nucleus feedback become more relevant at lower redshifts. (3) The ratio sSFR/sMAR has a peak value, which occurs around {M_vir}∼ 2× 10^{11} M_{⊙}. (4) The stellar mass density within 1 kpc, Σ1, is a good indicator of the galactic global sSFR. (5) Galaxies are statistically quenched after they reach a maximum in Σ1, consistent with theoretical expectations of the gas compaction model; this maximum depends on redshift. (6) In-situ star formation is responsible for most galactic stellar mass growth, especially for lower mass galaxies. (7) Galaxies grow inside-out. The marked change in the slope of the size-mass relation when galaxies became quenched, from d log {R_eff}/d log {M_*}∼ 0.35 to ∼2.5, could be the result of dry minor mergers.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- September 2017
- DOI:
- 10.1093/mnras/stx1172
- arXiv:
- arXiv:1703.04542
- Bibcode:
- 2017MNRAS.470..651R
- Keywords:
-
- galaxies: evolution;
- galaxies: haloes;
- galaxies: luminosity function;
- mass function;
- galaxies: star formation;
- cosmology: theory;
- mass function - galaxies: star formation;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 42 pages, 31 Figures. Accepted for publication in MNRAS. Typos corrected. The results presented in this paper are available via an interactive website: https://132.248.1.39/galaxy/galaxy_halo.html