Modeling the Hot Gaseous Halo in Galaxy Merger Simulations

Cosmological hydrodynamical simulations indicate that galaxies are mainly made out of dark matter halo, stellar disk, stellar bulge, gaseous disk and gaseous halo. While the first four components have been extensively considered in numerical simulations of binary galaxy mergers the effect of a hot gaseous halo has mostly been neglected. For the first time we present a series of hydrodynamical simulations of galaxy mergers, both major and minor, that include a diffuse, rotating, hot gaseous halo. We show that adding the hot gas component has a significant effect on the kinematics and internal structure of the merger remnants, like an increased abundance of fast rotators after major mergers and the reformation of a thin disk after minor mergers.