Constraints on massive black holes as dark matter candidates using Galactic globular clusters

This work considers the idea of massive black holes being the constituents of the Galactic dark matter halo. It constrains the maximum black hole mass to M(BH)less than or similar to 5 x 10(4) M circle dot by examining the influence of black holes on the population of globular clusters (GCs) in our Milky Way. In the adopted halo model, GCs are exposed to constant bombardment by halo objects on their orbits through the Galaxy and thus GCs will steadily gain internal energy. Depending on the mass of these halo objects and the structural parameters of the GCs, they can be disrupted on time-scales of a few billion years or less. These disruption time-scales are calculated using a modification of the well-known (classical) impulsive approximation and compared with direct N-body simulations of such encounter events to ensure that the method works correctly. For a set of 10 prototypical GC models and black hole masses ranging from 10(3) to 10(7) M circle dot, Monte Carlo simulations of 10000 encounter histories over the period of 10 billion years were calculated, at three different galactocentric distances, R=5, 10 and 15 kpc. These data were compared with the real GC population in our Galaxy and used to obtain the above constraint of M(BH)less than or similar to 5 x 10(4) M circle dot.