A Mosaic of the Coma Cluster of Galaxies with XMM-Newton
  The Coma cluster of galaxies was observed with XMM-Newton in 12 partially overlapping pointings. We present here the resulting X-ray map in different energy bands and discuss the large scale structure of this cluster. Many point sources were found throughout the observed area, at least 11 of them are coincident with bright galaxies. We also give a hardness ratio map at the so far highest angular resolution obtained for a cluster of galaxies. In this map we found soft regions at the position of bright galaxies, little variation in the central 15 arcmin, but some harder regions north of the line NGC 4874 - NGC 4889. 
Ulrich G. Briel, J. Patrick Henry, David H. Lumb, Monique Arnaud,   Doris Neumann, Nabila Aghanim, Rene Gastaud, Jonathan P....