The Disruption of Stellar Clusters Containing Massive Black Holes near the Galactic Center

Abstract

We present results from dynamical Monte Carlo simulations of dense star clusters near the Galactic center. These clusters sink toward the center of the Galaxy by dynamical friction. During their in-spiral, they may undergo core collapse and form an intermediate-mass black hole through runaway collisions. Such a cluster can then reach within a parsec of the Galactic center before it completely disrupts, releasing many young stars in this region. This scenario provides a natural explanation for the presence of the young stars observed near the Galactic center. Here we determine the initial conditions for this scenario to work, and we derive the mass distribution of cluster stars as a function of distance from the Galactic center. For reasonable initial conditions, we find that clusters massive enough for rapid in-spiral would include a larger number of massive stars (m à k 30 M) than currently observed in the in-spiral region. We point out several possible explanations for this apparent discrepancy.