Dynamics of Intermediate Mass Black Holes in Star Clusters
  We have followed the evolution of multi-mass star clusters containing massive central black holes by N-body simulations on the GRAPE6 computers of Tokyo University. We find a strong cluster expansion and significant structural changes of the clusters. Star clusters with IMBHs have power-law density profiles $rho ~ r^{-alpha}$ with slopes $alpha=1.55$ inside the influence sphere of the central black hole. This leads to a constant density profile of bright stars in projection, which rules out the presence of intermediate mass black holes in core collapse clusters. If the star clusters are surrounded by a tidal field, a central IMBH speeds up the destruction of the cluster until a remnant of a few hundred stars remains, which stays bound to the IMBH for a long time. We also discuss the efficiency of different detection mechanisms for finding IMBHs in star clusters. 
Holger Baumgardt (RIKEN), Simon Portegies Zwart (Amsterdam), Steve   McMillan (Drexel), Jun Makino (Univ. of Tokyo), Toshika...