Gamma rays from galaxy clusters

In recent work (Giler et al., 1980a) the authors have shown that a good model for the highest energy cosmic rays is one where they are generated in clusters of galaxies with a relatively flat production spectrum and then propagate with an energy dependent diffusion coefficient. There is evidence for a similar flat production spectrum (γ approximately= 2.1) for both protons and electrons in our own Galaxy (Giler et al., 1980b). Here they assume that the spectrum for clusters (specifically the VIRGO cluster) is independent of energy and an evaluation is made of the likely flux of γ-rays. (Auth.)