Upper limit on the primary photon fraction from the Pierre Auger Observatory
Astrophysics
2012-08-27 v1
Abstract
Based on observations of the depth of shower maximum performed with the hybrid detector of the Auger Observatory, an upper limit on the cosmic-ray photon fraction of 26% (at 95% confidence level) is derived for primary energies above 10^19 eV. Additional observables recorded with the surface detector array, available for a sub-set of the data sample, support the conclusion that a photon origin of the observed events is not favoured.
Cite
@article{arxiv.astro-ph/0507402,
title = {Upper limit on the primary photon fraction from the Pierre Auger Observatory},
author = {The Pierre Auger Collaboration},
journal= {arXiv preprint arXiv:astro-ph/0507402},
year = {2012}
}
Comments
4 pages, 4 figures. To be presented at the 29th ICRC, Pune, August 2005. The Pierre Auger author list is given at http://www.auger.org/admin