Gamma ray emission and stochastic particle acceleration in galaxy clusters

TL;DR

This paper discusses how gamma-ray emission and stochastic particle acceleration occur in galaxy clusters, focusing on interactions between relativistic particles and MHD turbulence during cluster mergers, predicting observable non-thermal emissions.

Contribution

It introduces a comprehensive model linking MHD turbulence with relativistic particle acceleration and gamma-ray emission in galaxy clusters, highlighting the role of mergers.

Findings

Gamma-ray emission is expected to be common in galaxy clusters.

Diffuse radio and hard X-ray emissions are linked to cluster mergers.

Relativistic particles interact with turbulence to produce non-thermal emissions.

Abstract

FERMI (formely GLAST) will shortly provide crucial information on relativistic particles in galaxy clusters. We discuss non-thermal emission in the context of general calculations in which relativistic particles (protons and secondary electrons due to proton-proton collisions) interact with MHD turbulence generated in the cluster volume during cluster mergers. Diffuse cluster-scale radio emission (Radio Halos) and hard X-rays are produced during massive mergers while gamma ray emission, at some level, is expected to be common in galaxy clusters.