The simplest model of galaxy formation I: A formation history model of galaxy stellar mass growth

TL;DR

This paper presents a simple, phenomenological model linking galaxy stellar mass growth to dark matter halo formation history, effectively reproducing observed stellar mass functions up to redshift 3.

Contribution

The authors introduce a minimal, two-function model that self-consistently connects galaxy growth to halo formation, improving predictions of stellar mass functions across cosmic time.

Findings

Successfully reproduces z=0 stellar mass functions

Improves fit to stellar mass functions up to z=3 by including redshift as a variable

Offers a useful tool for creating realistic mock galaxy samples

Abstract

We introduce a simple model to self-consistently connect the growth of galaxies to the formation history of their host dark matter haloes. Our model is defined by two simple functions: the "baryonic growth function" which controls the rate at which new baryonic material is made available for star formation, and the "physics function" which controls the efficiency with which this material is converted into stars. Using simple, phenomenologically motivated forms for both functions that depend only on a single halo property, we demonstrate the model's ability to reproduce the z=0 red and blue stellar mass functions. Furthermore, by adding redshift as a second input variable to the physics function we show that the reproduction of the global stellar mass function out to z=3 is improved. We conclude by discussing the general utility of our new model, highlighting its usefulness for creating mock galaxy samples which have a number of key advantages over those generated by other techniques.