Observations of the Coma cluster by Beppo-SAX have shown a hard X-ray excess in the spectrum that could be interpreted as the presence of a particle acceleration site. However, given that the hard X-ray instrument on board Beppo-SAX was non-imaging, existence of point sources could change this interpretation. The better angular resolution of INTEGRAL allowed us to analyze the morphology of the hard X-ray emission. Our results show that contamination by a very hard point source embedded in the cluster is highly unlikely, which strengthens the hypothesis of a particle acceleration site in the Coma region.

Proceedings of the 30th International Cosmic Ray Conference; Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.); Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008; Vol. 3 (OG part 2), pages 869-872