The impact of galaxy geometry and mass evolution on the survival of star
  clusters
  Direct N-body simulations of globular clusters in a realistic Milky Way-like
potential are carried out using the code NBODY6 to determine the impact of the
host galaxy disk mass and geometry on the survival of star clusters. A
relationship between disk mass and star cluster dissolution timescale is
derived. These N-body models show that doubling the mass of the disk from
5x10^10 solar masses to 10x10^10 solar masses halves the dissolution time of a
satellite star cluster orbiting the host galaxy at 6 kpc from the galactic
center. Different geometries in a disk of identical mass can determine either
the survival or dissolution of a star cluster orbiting within the inner 6 kpc
of the galactic center. Furthermore, disk geometry has measurable effects on
the mass loss of star clusters up to 15 kpc from the galactic center. N-body
simulations performed with a fine output time step show that at each disk
crossing the outer layers of star clusters experience an increase in velocity
dispersion of ~5% of the average velocity dispersion in the outer section of
star clusters. This leads to an enhancement of mass-loss -- a clearly
discernable effect of disk shocking. By running models with different
inclinations we determine that star clusters with an orbit perpendicular to the
Galactic plane have larger mass loss rates than both clusters evolving in the
Galactic plane or in an inclined orbit.
