Inward Bound—The Search for Supermassive Black Holes in Galactic Nuclei

摘要: Dynamical searches reveal central dark objects with masses"" 106 to 109.5 M0 in the Galaxy, M31, M32, M87, NGC 3115, 3377, 4258, and 4594. Indirect arguments suggest but do not prove that these are supermassive black holes (BHs) like those postulated as quasar engines. This paper reviews dynam­ ical search techniques, robustness of evidence, BH demographics. Stellar-dynamical evidence is generally more robust than gas-dynamical (gas velocities can be nongravitational), gas measurements reach closer Schwarzschild radius, 4258 they show a Keplerian rotation curve. A statistical survey finds BHs ""20% nearby E-Sbc galaxies, consistent predictions based on energetics. masses proportional mass bulge component. Most candidates inactive; some cases, abun­ dance fuel easily reconciled starvation. Flashes caused by accretion individual stars may provide test picture. I Visiting Astronomer, Canada-France-Hawaii Telescope (CFHT), operated National Research Council Canada, Ie Centre de la Recherche Scientifique France, University Hawaii.