Institute for Advanced Study Informal Astrophysics Seminar

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. Satellite subhalos must be well-resolved down to ~1% of their mass at infall, and many satellites experience tidal disruption prior to merging with the central galaxy. 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.