this paper we measure the stellar mass (M$_*$), dark matter halo mass (M$_{\mathrm{halo}}$), cold gas mass (M$_{\mathrm{cold}}$), SFR, M$_{\mathrm{B}}$, and $g$ $-$ $r$ color. Stellar mass is determined by adding the mass of each star particle identified by HOP to belong to a galaxy. The dark matter halo mass is calculated by summing the mass of all the dark matter particles out to r$_{200}$.

The cold gas mass is defined slightly differently in the low resolution versus the high resolution simulation due to differences in how the galaxy data sets were originally made, although as we now discuss the differences are minor for the purposes of this paper. In the low resolution simulation, M$_{\mathrm{cold}}$ is the sum of all HI gas within r$_{200}$. As noted in Section \[sec:boxes\], the fraction and density of neutral hydrogen is directly computed within the simulations. The high resolution data set includes values of the total gas within 100 kpc and 300 kpc with a temperature less than 10$^5$ K. Because this gas is at the peak of the cooling curve it quickly cools to $\sim$10$^4$ K, and there is therefore little effective difference in the temperatures of the two cold gas definitions. However, rather 