The central Parsec of the Milky Way: Star formation and central dark mass

Abstract

Recent high resolution near-infrared imaging and spectroscopy give detailed information about the structure, evolution and mass distribution in the nucleus of the Milky Way. The central parsec is powered by a cluster of luminous helium rich, blue supergiants. The most likely scenario for the formation of these massive stars is a burst of star formation a few million years ago. Radial velocity measurements for about 300 early and late type stars between 0.1 and 5 pc radius from the dynamic center now strongly favor the existence of a central dark mass of 2.5 to 3.3×106 M⊙ within 0.1 pc of the dynamic center. This central dark mass cannot be a cluster of neutron stars. It is either a compact cluster of stellar black holes or, most likely, a single massive black hole.