Evolution of the Galaxy - Dark Matter Connection and the Assembly of Galaxies in Dark Matter Halos

TL;DR

This paper introduces a new, self-consistent model for the galaxy-dark matter connection over cosmic time, accounting for subhalo accretion and satellite galaxy evolution, and validates it against diverse observational data.

Contribution

The model improves upon previous methods by incorporating subhalo accretion timing and satellite galaxy evolution, providing a comprehensive galaxy-halo relation from redshift 4 to present.

Findings

Model fits observational data within uncertainties

Supports the $\ m \

Predicts galaxy assembly histories and high-redshift galaxy clustering

Abstract

We present a new model to describe the galaxy-dark matter connection across cosmic time, which unlike the popular subhalo abundance matching technique is self-consistent in that it takes account of the facts that (i) subhalos are accreted at different times, and (ii) the properties of satellite galaxies may evolve after accretion. Using observations of galaxy stellar mass functions out to $z \sim 4$, the conditional stellar mass function at $z\sim 0.1$ obtained from SDSS galaxy group catalogues, and the two-point correlation function (2PCF) of galaxies at $z \sim 0.1$ as function of stellar mass, we constrain the relation between galaxies and dark matter halos over the entire cosmic history from $z \sim 4$ to the present. This relation is then used to predict the median assembly histories of different stellar mass components within dark matter halos (central galaxies, satellite galaxies, and halo stars). We also make predictions for the 2PCFs of high-$z$ galaxies as function of stellar mass. Our main findings are the following: (i) Our model reasonably fits all data within the observational uncertainties, indicating that the $\Lambda$CDM concordance cosmology is consistent with a wide variety of data regarding the galaxy population across cosmic time. (ii) ... [abridged]