2008/01/09 by M. Ostrowski, Ostrowski, M. · 1 citation
Engineering · Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Cosmic Phenomena #FOS: Physical sciences #Gamma-ray bursts and supernovae #Particle Accelerators and Free-Electron Lasers #astro-ph
paper · pdf · doi:10.48550/arxiv.0801.1339
A talk given at "Jean-Pierre Lasota, X-ray binaries, accretion disks and compact stars" (October 2007); Abramowicz, M. Ed., New Astron. Rev., in press
openalex publication_date 2008/01/09 · arxiv created 2008/01/11 · arxiv updated 2011/11/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A review of theoretical results on cosmic ray first-order Fermi acceleration at relativistic shock waves is presented, with recent results substantially changing the existing knowledge on these processes. In particular one can not expect such shocks to form particle distributions extending to very high energies. Instead, distributions with the shock compressed injected component followed by a more or less extended high energy tail are usually created. Increasing the shock Lorentz factor leads to steepening of the energetic tail. An observational check of real electron spectra in the Cyg A hot spots provides results clearly deviating from the standard expectations. The spectrum consist of a very flat low energy part (sigma ~1.5)up to electron energies ~1 GeV, and a much steeper part (sigma > 3)at higher energies. We conclude with remarks on the Fermi second-order processes acting in relativistic plasmas, possibly the main accelerating agent for very high energy cosmic rays.