2002/07/22 by V. Petrosian, Vahé Petrosian, Petrosian, Vahé
Engineering · Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Cosmic Phenomena #FOS: Physical sciences #Particle Accelerators and Free-Electron Lasers #Particle accelerators and beam dynamics #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0207481
10 pages, 3 figures. Invited Talk to appear in thr Proc. of "Matter and Energy in Clusters of Galaxies", April 23-27, Taiwan
arxiv created 2002/07/22 · openalex publication_date 2002/07/22 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Recent observations of excess radiation at extreme ultraviolet and hard X-ray\nenergies straddling the well known thermal soft X-ray emission have provided\nnew tools and puzzles for investigation of the acceleration of nonthermal\nparticles in the intercluster medium of clusters of galaxies. It is shown that\nthese radiations can be produced by the inverse Compton upscattering of the\ncosmic microwave background photons by the same population of relativistic\nelectrons that produce the well known diffuse radio radiation via the\nsynchrotron mechanism. It is shown that the commonly discussed discrepancy\nbetween the value of the magnetic field required for the production of these\nradiation with that obtained from Faraday rotation measures could be resolved\nby more realistic models and by considerations of observational selection\neffects. In a brief discussion of the acceleration process it is argued that\nthe most likely scenario is reacceleration of injected relativistic electrons\ninvolving shocks and turbulence. The seed electrons cannot be the background\nthermal electrons because of energetic considerations, and a steady state\nsituation may not agree with the details of the observed spectra. Episodic\ngeneration of shocks and turbulence or episodic injection of relativistic\nelectrons is a more likely scenario for acceleration.\n