Gamma-radiation from the cluster Abell 3376

Abstract

We estimate the radiation produced at high energies by the cluster of galaxies Abell 3376, which is characterized by double opposite, giant ringlike radio structures. These recently detected radio relics support the presence of relativistic particles that are assumed to be accelerated in-situ by a diffusive shock mechanism. We calculate the spectral energy distribution resulting from the most relevant non-thermal processes (synchrotron radiation, inverse Compton (IC) scattering, relativistic Bremsstrahlung, and inelastic proton-proton collisions). From our specific model, we find that the major radiative component at high energies is IC scattering. Hadronic interactions would yield a minor contribution to the overall non-thermal emission, but would dominate at ultra-high energies. The nearby cluster Abell 3376 might be detectable at gamma-rays by GLAST satellite and Cherenkov arrays.