Satellite galaxy merging and disruption

Andrew Wetzel


Dark matter halos that merge with larger halos persist as subhalos, which  host satellite galaxies.  While subhalos are rapidly stripped of their dark mass, the compact luminous material remains intact for some time.  I use a high-resolution, cosmological N-body simulation to explore satellite galaxy merging and tidal disruption.  Using abundance matching to assign stellar mass to subhalos, I compare with observed satellite fractions, galaxy clustering, and cluster luminosity functions.  These results imply that satellite subhalos must be well-resolved down to ~1% of their mass at infall to robustly trace the galaxy population.  I also explore a simple analytic model based on dynamical friction for satellite infall.  Finally, I examine the orbital distribution of infalling satellites and its evolution with halo mass and redshift.