Discovery of a Supermassive Black Hole in a Bulge-less Galaxy
Abstract
Recent observational and theoretical work suggest that every galaxy hosts a supermassive black hole in its nucleus and that the mass of the black hole depends upon the mass of the galactic bulge. We initiated a program to look for accreting supermassive black holes in centers of normal (i.e. inactive) galaxies. We detected several X-ray sources in our Chandra survey, but it was difficult to separate supermassive black holes from contaminants such as X-ray binaries. We obtained XMM spectra with the goal of identifying Chandra sources. We have now analyzed one spectrum which shows the source to be reflection dominated, and almost certainly an active galactic nucleus. The importance of this result is that we seem to have discovered a supermassive black hole in a bulge-less galaxy. This is completely contrary to the expectations based on the MBH--sigma relation and implies that a bulge is not necessary for the existence of a supermassive black hole in the nucleus of a galaxy. The BH mass may be related to the dark matter halo instead. (We are working on confirming our initial result. We have also started to analyze one more XMM spectrum. Results will be ready before the HEAD meeting.)
- Publication:
-
AAS/High Energy Astrophysics Division #11
- Pub Date:
- March 2010
- Bibcode:
- 2010HEAD...11.2004M