Structure of the globular cluster M15 and constraints on a massive central black hole

Abstract

Globular clusters could harbor massive central black holes (BHs), just as galaxies do. So far, no unambiguous detection of a massive BH has been reported for any globular cluster. However, the dense core-collapsed cluster M15 seems to be a good candidate. I review the available photometric and kinematic data for this cluster. Both are consistent with a BH of approximately 2000 solar masses, although such a BH is not unambiguously required by the data. I discuss some ongoing studies with Keck and HST which should shed more light on this issue in the coming years.

To appear in `Black Holes in Binaries and Galactic Nuclei', Proceedings of an ESO Workshop in September 1999, Kaper L., van den Heuvel E. P. J., Woudt P. A., eds., Springer-Verlag, 2000. 6 pages LaTeX with 1 PostScript figure