The Effects of Dwarf Galaxies on the Orbital Evolution of Galactic
  Globular Clusters
  We investigate the effect that dwarf galaxies have on the orbits, tidal
histories, and assumed formation environment of Milky Way globular clusters. We
determine the orbits of the Milky Way's 150 globular clusters in a
gravitational potential both with and without dwarf galaxies. We find that the
presence of a small number of satellite galaxies can affect the orbits of many
of the globular clusters. Over 12 Gyr, we find that the semi-major axis and
orbital eccentricity of individual clusters fluctuate with dispersions on the
order of $\sim 10\%$ and $\sim 4\%$, respectively. Outer clusters are more
strongly affected by dwarf galaxies than inner clusters, with their semi-major
axis and orbital eccentricities fluctuating by more than $\sim 15\%$ and $\sim
5\%$, respectively. Using detailed $N$-body simulations of select clusters, we
find that altering their orbital histories can lead to different mass loss
rates and structural evolution. Furthermore, we caution against using
kinematics alone to identify whether a Galactic cluster formed in-situ or was
accreted during a past merger event as these values are no longer conserved.
The presence of dwarf galaxies causes the orbital energies and actions of
individual clusters to evolve over time, spanning a wider range than that
coming from random uncertainties in a cluster's proper motions and radial
velocity.
