Accreted Globular Clusters in External Galaxies: Why Adaptive Dynamics
  is not the Solution
  Many astrophysical and galaxy-scale cosmological problems require a well
determined gravitational potential which is often modeled by observers under
strong assumptions. Globular clusters (GCs) surrounding galaxies can be used as
dynamical tracers of the luminous and dark matter distribution at large (kpc)
scales. A natural assumption for modeling the gravitational potential is that
GCs accreted in the same dwarf galaxy merger event move at the present time on
similar orbits in the host galaxy and should therefore have similar actions. We
investigate this idea in one realistic Milky Way like galaxy of the
cosmological N-body simulation suite Auriga. We show how the actions of
accreted stellar particles in the simulation evolve and that minimizing the
standard deviation of GCs in action space, however, cannot constrain the true
potential. This approach known as adaptive dynamics does therefore not work for
accreted GCs.
