Non thermal emission from Abell 754

Abstract In the first part we briefly review the results of the BeppoSAX observations regarding the search for non-thermal emission from clusters of galaxies exploiting the unique spectral capabilities of the PDS. For the first time non-thermal radiation has been detected in the Coma cluster, and then in Abell 2256. In the second part we show a more recent BeppoSAX observation of Abell 754 that reports a non-thermal excess with respect to the thermal emission at energies greater than ∼ 45 keV, at a confidence level slightly above 3σ. The presence of a radio halo in A754, considered the prototype of a merging cluster, reinforces the link between formation of Mpc-scale radio regions and very recent or current merger processes. The radio results combined with the hard X-ray excess detected by BeppoSAX give information on the origin of the electron population responsible for non-thermal phenomena in galaxy clusters.