======================================================================== G C N E W S * Newsflash * - The Newsletter for Galactic Center Research - gcnews@mpifr-bonn.mpg.de http://www.mpifr-bonn.mpg.de/gcnews ======================================================================== Vol. 14, No. 2 Sep 24, 2001 Due to a (scheduled) power-outage and extensive traveling in recent weeks the GCNEWS server was down for a couple of days. If you had any problems in submitting papers or contacting us we apologize and would ask you to please try again. Recently submitted papers: -------------------------- 1) Rapid X-ray flaring from the direction of the supermassive black hole at the Galactic Centre (Baganoff et al., Nature) ------------------------------------------------------------------------ Email : fkb@space.mit.edu Title : Rapid X-ray flaring from the direction of the supermassive black hole at the Galactic Centre Author(s): F. K. Baganoff(1), M. W. Bautz(1), W. N. Brandt(2), G. Chartas(2), E. D. Feigelson(2), G. P. Garmire(2), Y. Maeda(2,3), M. Morris(4), G. R. Ricker(1), L. K. Townsley(2), and F. Walter(5) Institute: (1) Center for Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139-4307, USA (2) Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802-6305, USA (3) Institute of Space and Astronautical Science, 3-1-1 Yoshinodai, Sagamihara, 229-8501, Japan (4) Department of Physics and Astronomy, University of California at Los Angeles, Los Angeles, CA 90095-1562, USA (5) Department of Astronomy, California Institute of Technology, Pasadena, CA 91125, USA Paper : Nature, 413, 45 (2001) EPrint : astro-ph/0109367 Abstract: Most galactic nuclei are now believed to harbour supermassive black holes. Studies of stellar motions in the central few light-years of our Milky Way Galaxy indicate the presence of a dark object with a mass of about 2.6 million solar masses. This object is spatially coincident with Sagittarius A* (Sgr A*), the unique compact radio source located at the dynamical centre of our Galaxy. By analogy with distant quasars and nearby active galactic nuclei (AGN), Sgr A* is thought to be powered by the gravitational potential energy released by matter as it accretes onto a supermassive black hole. However, Sgr A* is much fainter than expected in all wavebands, especially in X-rays, casting some doubt on this model. Recently, we reported the first strong evidence of X-ray emission from Sgr A*. Here we report the discovery of rapid X-ray flaring from the direction of Sgr A*. These data provide compelling evidence that the X-ray emission is coming from accretion onto a supermassive black hole at the Galactic Centre, and the nature of the variations provides strong constraints on the astrophysical processes near the event horizon of the black hole. ------------------------------------------------------------------------ (Older versions of the Newsflash can be found at the gcnews web-page) ======================================================================== Edited by Angela Cotera Heino Falcke & Sera Markoff (cotera@as.arizona.edu) (hfalcke,smarkoff@mpifr-bonn.mpg.de) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - For Abstract submission please send the (La)Tex file of your paper to gcnews@mpifr-bonn.mpg.de ========================================================================