Hard X-Ray Emission from Clusters of Galaxies



We analyze the origin of the flux of hard X-rays from the Coma cluster observed by the Beppo-SAX telescope. It is used to assume that this flux is produced by nonthermal particles accelerated in the Coma medium. We show, however, that in the case of in-situ acceleration of particles from the thermal pool the bremsstrahlung radiation of hard X-rays is generated by thermal particles whose spectrum is distorted by the acceleration. This mimic the effect of a two-temperature thermal spectrum. A power-law nonthermal spectrum of accelerated particles is formed at much higher energies.

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On 16 Jul 1999, 09:19.