Particle injection and reacceleration in clusters of galaxies and the EUV excess: the case of Coma

✍ Scribed by G. Brunetti; G. Setti; L. Feretti; G. Giovannini

• Book ID: 104426376
• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 226 KB
• Volume: 6
• Category: Article
• ISSN: 1384-1076
• DOI: 10.1016/s1384-1076(00)00048-8

✦ Synopsis

We calculate the energy distribution of the relativistic particles injected in the ICM during a phase of reacceleration of the relativistic particles in the cluster volume. We apply our results to the case of the Coma cluster in which recent merging activity and the presence of a radio halo may suggest that reacceleration processes are efficient. We find that the electron population injected in the central part of the cluster by the head tail radio galaxy NGC 4869 may account for a large fraction, if not all, of the detected EUV excess via inverse Compton scattering of the cosmic microwave background (CMB) photons. If radio haloes are powered by reacceleration mechanisms active in the cluster volume, moderate non-thermal EUV excesses 42 21

(of the order |125?10 erg s ) should be a common feature of clusters containing powerful head tail radio galaxies and / or AGNs.