What determines satellite galaxy disruption?
  In hierarchical structure formation, dark matter halos that merge with larger
halos can persist as subhalos. These subhalos are likely hosts of visible
galaxies. While the dense halo environment rapidly strips subhalos of their
dark mass, the compact luminous material can remain intact for some time,
making the correspondence of galaxies with severely stripped subhalos unclear.
Many galaxy evolution models assume that satellite galaxies eventually merge
with their central galaxy, but this ignores the possibility of satellite tidal
disruption. We use a high-resolution $N$-body simulation of cosmological volume
to explore satellite galaxy merging/disruption criteria based on dark matter
subhalo dynamics. We explore the impact that satellite merging/disruption has
on the Halo Occupation Distribution and radial profile of the remnants. Using
abundance matching to assign stellar mass/luminosity to subhalos, we compare
with observed galaxy clustering, satellite fractions, cluster satellite
luminosity functions, finding that subhalos reproduce well these observables on
all scales. Our results imply that satellite subhalos corresponding to >0.2L*
galaxies must be well-resolved down to 1-3% of their mass at infall to robustly
trace the galaxy population. We also explore a simple analytic model based on
dynamical friction for satellite galaxy infall, finding good agreement with our
subhalo catalog and observations.
