Chandra X-ray Observatory
Formerly called AXAF, Chandra was launched on July 23, 1999, and is the largest and most sophisticated X-ray observatory to date.
Web Site: http://chandra.harvard.edu/
Lead Investigator: Dr Ann Hornschemeier
X-ray emission can originate from energetic hot gas as it swirls around a black hole before it is eventually "sucked in". The 0.5 arcsecond resolution of Chandra, which corresponds to 235 parsecs at the distance of Coma, is capable of determining if any X-ray sources are coincident with galactic nuclei, where at least in large galaxies we know that supermassive black holes exist. Our survey should help to provide a lower limit to the sizes of galaxies which host massive black holes. In addition we should be able to determine if a galaxy's environment (i.e., the densely populated core region versus the less dense outer regions of the cluster) affects the fuelling of these black holes.In addition to discovering new active galactic nuclei powered by massive black holes, the survey will also uncover numerous X-ray binary sources, involving neutron stars or stellar mass black holes.
The core region of the Coma cluster is being studied by Vikhlinin et al., while
Hornschemeier et al. (2006) is looking at the infall region.