Uncovering Mass Segregation with Galaxy Analogues in Dark Matter
  Simulations
  We investigate mass segregation in group and cluster environments by
identifying galaxy analogues in high-resolution dark matter simulations.
Subhalos identified by the AHF and ROCKSTAR halo finders have similar mass
functions, independent of resolution, but different radial distributions due to
significantly different subhalo hierarchies. We propose a simple way to
classify subhalos as galaxy analogues. The radial distributions of galaxy
analogues agree well at large halo-centric radii for both AHF and ROCKSTAR but
disagree near parent halo centres where the phase-space information used by
ROCKSTAR is essential.
  We see clear mass segregation at small radii (within $0.5\,r_{vir}$) with
average galaxy analogue mass decreasing with radius. Beyond the virial radius,
we find a mild trend where the average galaxy analogue mass increases with
radius. These mass segregation trends are strongest in small groups and
dominated by the segregation of low mass analogues. The lack of mass
segregation in massive galaxy analogues suggests that the observed trends are
driven by the complex accretion histories of the parent halos rather than
dynamical friction.
