The Sensitivity of Harassment to Orbit: Mass Loss from Early-Type Dwarfs
  in Galaxy Clusters
  We conduct a comprehensive numerical study of the orbital dependence of
harassment on early-type dwarfs consisting of 168 different orbits within a
realistic, Virgo-like cluster, varying in eccentricity and pericentre distance.
We find harassment is only effective at stripping stars or truncating their
stellar disks for orbits that enter deep into the cluster core. Comparing to
the orbital distribution in cosmological simulations, we find that the majority
of the orbits (more than three quarters) result in no stellar mass loss. We
also study the effects on the radial profiles of the globular cluster systems
of early-type dwarfs. We find these are significantly altered only if
harassment is very strong. This suggests that perhaps most early-type dwarfs in
clusters such as Virgo have not suffered any tidal stripping of stars or
globular clusters due to harassment, as these components are safely embedded
deep within their dark matter halo. We demonstrate that this result is actually
consistent with an earlier study of harassment of dwarf galaxies, despite the
apparent contradiction. Those few dwarf models that do suffer stellar stripping
are found out to the virial radius of the cluster at redshift=0, which mixes
them in with less strongly harassed galaxies. However when placed on
phase-space diagrams, strongly harassed galaxies are found offset to lower
velocities compared to weakly harassed galaxies. This remains true in a
cosmological simulation, even when halos have a wide range of masses and
concentrations. Thus phase-space diagrams may be a useful tool for determining
the relative likelihood that galaxies have been strongly or weakly harassed.
