supplying the formation time, metallicity and stellar mass. M$_{\mathrm{B}}$ is calculated as M$_{\mathrm{B}}$ $=$ $\mathrm{M_g}$ + 0.313$\times$$(\mathrm{M_g}-\mathrm{M_r}) + 0.2271$ (Lupton 2005). The SFR for a galaxy is calculated based on the creation time and mass of each star particle.

Local Density {#sec:localdensity}
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We choose to use dark matter mass to define the local environment because it is a fundamental measure of the local mass in a region. Further, using dark matter mass is not plagued by the uncertainties in using galaxy counts as a measure of local density. In simulations the galaxy number count could be affected by resolution issues that may affect galaxy number counts, while in observational samples local galaxy counts may be affected by projection effects due to lack of means to distinguish between peculiar velocity and Hubble velocity.

We define the local environment by measuring the dark matter mass in spheres with a comoving radius of 1 $h^{-1}$ Mpc. In this paper we focus on how galaxy SFRs and gas content may be affected on scales larger than the virial radius (all halos except the cluster halo have virial radii less than 1 $h^{-1}$ Mpc), for example whether residing in collapsed filaments and pancakes would 