The broadband spectrum of galaxy clusters

Brandon Wolfe, Fulvio Melia

Research output: Contribution to journalArticle

7 Citations (Scopus)

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 intracluster medium (ICM) from a thermal profile via Coulomb collisions between the quasi-thermal 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.

Original languageEnglish (US)
Pages (from-to)156-162
Number of pages7
JournalAstrophysical Journal
Volume675
Issue number1
DOIs
StatePublished - Mar 1 2008

Fingerprint

galaxies
broadband
electron
power law
collision
Coulomb collisions
Fermi Gamma-ray Space Telescope
electrons
protons
coma
kinetic equations
hadrons
bremsstrahlung
electron scattering
merger
injection
collisions
causes
decay
radio

Keywords

  • Acceleration of particles
  • Galaxies: clusters: individual (Coma)
  • Plasmas
  • Radiation mechanisms: Nonthermal
  • Relativity
  • X-rays: galaxies

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

The broadband spectrum of galaxy clusters. / Wolfe, Brandon; Melia, Fulvio.

In: Astrophysical Journal, Vol. 675, No. 1, 01.03.2008, p. 156-162.

Research output: Contribution to journalArticle

Wolfe, Brandon ; Melia, Fulvio. / The broadband spectrum of galaxy clusters. In: Astrophysical Journal. 2008 ; Vol. 675, No. 1. pp. 156-162.
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