0620007

The presence of excess emission from the Coma cluster above 10 keV has been claimed from BeppoSAX and RXTE observations. However an independent analysis of the same BeppoSAX data by another group still casts doubts on this result. Confirmation of this result is of prime importance to study the population of relativistic electrons to measure directly the magnetic field in the cluster and to understand the state of the gas in the cluster. Existing INTEGRAL data (1 Ms) allowed us to to identify a region South-West of the cluster core in excess compared to the 1-10 keV profile. We found that the position of the excess coincides with the 1.4 GHz radio peak which strongly suggests that the emission from this region is non-thermal. However it is not yet possible to exclude the possibility that the emission is due to very hot thermal gas. Therefore we propose another 1 Ms INTEGRAL observation of the Coma cluster that will allow usto detect the source up to 80 keV in order to reveal the nature of the excess. Moreover we will be able to better characterize the morphology of the cluster above 18 keV and study more extensively the high-energy emitting region discovered in existing INTEGRAL data which is a unique use of INTEGRAL?s imaging capabilities. [truncated! Please see actual data for full text]