Some observational tests of a minimal galaxy formation model
  Dark matter simulations can serve as a basis for creating galaxy histories
via the galaxy-dark matter connection. Here, one such model by Becker (2015) is
implemented with several variations on three different dark matter simulations.
Stellar mass and star formation rates are assigned to all simulation subhalos
at all times, using subhalo mass gain to determine stellar mass gain. The
observational properties of the resulting galaxy distributions are compared to
each other and observations for a range of redshifts from 0-2. Although many of
the galaxy distributions seem reasonable, there are noticeable differences as
simulations, subhalo mass gain definitions, or subhalo mass definitions are
altered, suggesting that the model should change as these properties are
varied. Agreement with observations may improve by including redshift
dependence in the added-by-hand random contribution to star formation rate.
There appears to be an excess of faint quiescent galaxies as well (perhaps due
in part to differing definitions of quiescence). The ensemble of galaxy
formation histories for these models tend to have more scatter around their
average histories (for a fixed final stellar mass) than the two more predictive
and elaborate semi-analytic models of Guo et al (2013) and Henriques et al
(2015), and require more basis fluctuations (using PCA) to capture 90 percent
of the scatter around their average histories.
  The codes to plot model predictions (in some cases alongside observational
data) are publicly available to test other mock catalogues at
https://github.com/jdcphysics/validation . Information on how to use these
codes is in the appendix.
