English

Heavy Cosmic Ray Nuclei from Extragalactic Sources above 'The Ankle'

Astrophysics 2009-11-20 v1

Abstract

A very recent observation by the Auger Observatory group claims strong evidence for cosmic rays above 56 EeV being protons from Active Galactic Nuclei. If, as would be expected, the particles above the ankle at about 2 EeV are almost all of extragalactic origin then it follows that the characteristics of the nuclear interactions of such particles would need to be very different from conventional expectation -- a result that follows from the measured positions of 'shower maximum' in the Auger' work. Our own analysis gives a different result, viz that the detected particles are still 'massive' specifically with a mean value of <ln A> = 2.2 +- 0.8. The need for a dramatic change in the nuclear physics disappears.

Keywords

Cite

@article{arxiv.0712.3403,
  title  = {Heavy Cosmic Ray Nuclei from Extragalactic Sources above 'The Ankle'},
  author = {Tadeusz Wibig and Arnold W. Wolfendale},
  journal= {arXiv preprint arXiv:0712.3403},
  year   = {2009}
}

Comments

10 pages

R2 v1 2026-06-21T09:56:11.251Z