Simulating Globular Clusters in Dark Matter Sub-Halos

A cosmological zoom-in simulation which leads to a Milky Way like halo is started at redshift 7. The initial dark matter distribution is augmented with globular star clusters, composed of 4 M_sun star particles, placed in the sub-halos on three different sets of orbits: in the range of 10\% and 1\% of the sub-halo virial radii, and, at the exact center of the sub-halos. The three sets of star clusters end with median orbital radii of 30, 5 and 16 kpc, losing about 2, 50 and 15\% of their mass, respectively and have very substantially different stellar kinematics beyond about 3 half mass radii. The clusters started at larger sub-halo radii have a velocity dispersion that declines to 15-25\% of the central value in the outer 5-20 half mass radius region. The clusters started at sub-halo centers have a rise in velocity dispersion beyond 3-5 half mass radii, some reaching values of twice the central velocity dispersion at 10 half mass radii. The sub-halo centered clusters tend to have isotropic velocity distributions at large radii, whereas the isolated ones have a region of radial oriented velocity ellipsoid.