High-energy gamma-ray and neutrino backgrounds from clusters of galaxies and radio constraints

Understand

Cosmic-ray protons accumulate for cosmological times in clusters of galaxies as their typical radiative and diffusive escape times are longer than the Hubble time.

• Their hadronic interactions with protons of the intra-cluster medium generate secondary electrons, gamma-rays and neutrinos.
• We here estimate the contribution from clusters to the diffuse gamma-ray and neutrino backgrounds.
• We model the cluster population by means of their mass function, using a phenomenological luminosity-mass relation applied to all clusters, as well as a detailed semi-analytical model.