Greg Snyder, Harvard University Title: Poststarburst Galaxies as the Aftermath of Gas-Rich Mergers Abstract: I will discuss efforts to leverage realistic models of galaxy interactions against observations in order to test the role of mergers in the assembly of galaxies. In one study, models of poststarburst galaxies are constructed by combining fully three-dimensional hydrodynamic simulations of galaxy mergers with radiative transfer calculations of dust attenuation. Properties of the merging galaxies are varied systematically, showing that the lifetime and properties of this phase are strong functions of merger scenario. Combined with empirical merger rates, the model lifetimes predict rapidly-rising poststarburst fractions as a function of redshift that are consistent with results of large spectroscopic surveys, resolving tension between the observed abundance and that predicted when one assumes the duration is uniformly the lifetime of A stars (~1 Gyr). Seen shortly after a bright starburst/AGN phase in violent mergers, poststarburst galaxies offer a unique opportunity to study the formation of bulges, as well as the effects of quasar and star formation feedback on the gas reservoir and remnant.