X-ray Evidence for Supermassive Black Holes at the Centers of Nearby Galaxies
Abstract
Description
We first present a short overview of X-ray probes of the black hole region of active galaxies (AGN) and then concentrate on the X-ray search for supermassive black holes (SMBHs) in optically non-active galaxies.
The first part focuses on recent results from the X-ray observatories Chandra and XMM-Newton which detected a wealth of new spectral features which originate in the nuclear region of AGN.
In the last few years, giant-amplitude, non-recurrent X-ray flares have been observed from several non-active galaxies. All of them share similar properties, namely: extreme X-ray softness in outburst, huge peak luminosity (up to ~10^{44} erg/s), and the absence of optical signs of Seyfert activity. Tidal disruption of a star by a supermassive black hole is the favored explanation of these unusual events. The second part provides a review of the initial X-ray observations, follow-up studies,and the relevant aspects of tidal disruption models studied in the literature.
Ludwig-Biermann Award Lecture, to appear in: Reviews in Modern Astronomy 15, R. Schielicke (ed.), Springer-Verlag, p. 27-56 (2002); preprint incl. full-size figures is available at http://www.xray.mpe.mpg.de/~skomossa/
Ludwig-Biermann Award Lecture, to appear in: Reviews in Modern Astronomy 15, R. Schielicke (ed.), Springer-Verlag, p. 27-56 (2002); preprint incl. full-size figures is available at http://www.xray.mpe.mpg.de/~skomossa/