Journal Article

Ultra-high-energy cosmic rays from the radio lobes of active galactic nuclei

F. Fraschetti and F. Melia

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 391, issue 3, pages 1100-1106
Published in print December 2008 | ISSN: 0035-8711
Published online November 2008 | e-ISSN: 1365-2966 | DOI:
Ultra-high-energy cosmic rays from the radio lobes of active galactic nuclei

More Like This

Show all results sharing this subject:

  • Astronomy and Astrophysics


Show Summary Details


In the past year, the HiRes and Auger collaborations have reported the discovery of a high-energy cut-off in the ultra-high-energy cosmic ray spectrum, and an apparent clustering of the highest energy events towards nearby active galactic nuclei. Consensus is building that such ∼1019–1020 eV particles are accelerated within the radio-bright lobes of these sources, but it is not yet clear how this actually happens. In this paper, we report (to our knowledge) the first treatment of stochastic particle acceleration in such environments from first principles, showing that energies ∼1020 eV are reached in ∼106 yr for protons. However, our findings reopen the question regarding whether the high-energy cut-off is due solely to propagation effects, or whether it does in fact represent the maximum energy permitted by the acceleration process itself.

Keywords: acceleration of particles; plasmas; turbulence; cosmic rays; galaxies: active; galaxies: nuclei

Journal Article.  5745 words.  Illustrated.

Subjects: Astronomy and Astrophysics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.