The Dynamical Evolution of Accreted Star Clusters in the Milky Way
  We perform $N$-body simulations of star clusters in time-dependant galactic
potentials. Since the Milky Way was built-up through mergers with dwarf
galaxies, its globular cluster population is made up of clusters formed both
during the initial collapse of the Galaxy and in dwarf galaxies that were later
accreted. Throughout a dwarf-Milky Way merger, dwarf galaxy clusters are
subject to a changing galactic potential. Building on our previous work, we
investigate how this changing galactic potential affects the evolution of a
cluster's half mass radius. In particular, we simulate clusters on circular
orbits around a dwarf galaxy that either falls into the Milky Way or evaporates
as it orbits the Milky Way. We find that the dynamical evolution of a star
cluster is determined by whichever galaxy has the strongest tidal field at the
position of the cluster. Thus, clusters entering the Milky Way undergo changes
in size as the Milky Way tidal field becomes stronger and that of the dwarf
diminishes. We find that ultimately accreted clusters quickly become the same
size as a cluster born in the Milky Way on the same orbit. Assuming their
initial sizes are similar, clusters born in the Galaxy and those that are
accreted cannot be separated based on their current size alone.
