Monsters at the Heart of Galaxy Formation
  Surveys with the Hubble Space Telescope find supermassive black holes (BHs) of 10**6 to 10**9.5 solar masses in every galaxy that has an elliptical-galaxy-like "bulge" component. BHs appear to be standard equipment in galaxy bulges. At the 2000 June meeting of the American Astronomical Society, two groups announced the discovery of a tight correlation between BH mass and the global velocity dispersion of stars in the host galaxy bulge (astro-ph/0006053 and astro-ph/0006289). Also, BH mass scales with bulge mass; the median BH mass fraction is 0.15 % of the bulge mass. In contrast, BH mass does not scale with disk properties. Pure disk galaxies - ones that lack a bulge component - must have BH mass fractions that are much smaller than the BH mass fractions in bulges. These results imply a close connection between BH growth and bulge (but not disk) formation. Observations increasingly support the hypothesis that the major events that form a bulge or elliptical galaxy and the main growth phases of its BH - when it shone like a quasar - were the same events. These and other results are leading to a profound change in how astronomers view BHs. More than just exotica needed to explain rare active galactic nuclei, they are becoming an integral part of our understanding of galaxy formation. 
John Kormendy (Department of Astronomy, University of Texas at Austin)