The Broadband Spectrum of Galaxy Clusters

Abstract

We examine whether nonthermal protons energized during a cluster merger are simultaneously responsible for the Coma cluster's diffuse radio flux (via secondary decay) and the departure of its intra-cluster medium (ICM) from a thermal profile via Coulomb collisions between the quasithermal electrons and the hadrons. Rather than approximating the influence of nonthermal proton/thermal electron collisions as extremely rare events which cause an injection of nonthermal, power-law electrons (the `knock-on' approximation), we self-consistently solve (to our knowledge, for the first time) the covariant kinetic equations for the two populations. The electron population resulting from these collisions is out of equilibrium, yet not a power law, and importantly displays a higher bremsstrahlung radiative efficiency than a pure power law. Observations with GLAST will test this model directly.

Accepted for publication in ApJ

References in corpus (2)

• Differential Form of the Collision Integral for a Relativistic Plasma
• In-situ acceleration of subrelativistic electrons in the Coma halo and the halo's influence on the Sunyaev-Zeldovich effect

Cited by in corpus (8)

• Simulating cosmic rays in clusters of galaxies - III. Non-thermal scaling relations and comparison to observations
• Chandra measurements of non-thermal-like X-ray emission from massive, merging, radio-halo clusters
• Neutrinos and Gamma Rays from Galaxy Clusters
• Stochastic particle acceleration and the problem of backgroud plasma overheating
• Can electron distribution functions be derived through the Sunyaev-Zel'dovich effect?
• On the influence of high energy electron populations on metal abundance estimates in galaxy groups and clusters
• Multi-frequency constraints on the non-thermal pressure in galaxy clusters
• High-Energy Neutrino Production in Clusters of Galaxies