Hard X-Ray Observations Of A Sample Of Clusters Of Galaxies

The BeppoSAX public archive has been searched for hard X-ray data obtained with the PDS instruments on observations of clusters of Galaxies. Of the fourteen objects analysed with the standard procedure, eight are detected with a significance > 5 sigma in the 13-00 keV range, while for the remaining objects a marginal detection (3 < sigma < 5) can be claimed. A preliminary spectral analysis of source data having more than 10 sigma detection indicates that at least in some cases a second component is present besides the thermal bremsstrahlung emission that dominates at low energy. However, the lack of imaging capability in the PDS prevents discrimination between an origin of this radiation in terms of an AGN or diffuse cluster emission. The potential of the INTEGRAL. instruments to detect this high energy emission in Clusters of Galaxies is briefly discussed.