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30th International Cosmic Ray Conference - ICRC'07, Merida : Mexique (2007)
The ultra-high energy cosmic ray spectrum and Fermi shock acceleration.
M. Kachelriess, D.V. Semikoz1
(2008)

The energy spectrum of ultra-high energy cosmic rays (UHECR) is usually calculated for sources with identical properties. Assuming that all sources can accelerate UHECR protons to the same extremely high maximal energy E_max > 10^{20} eV and have the steeply falling injection spectrum 1/E^{2.7}, one can reproduce the measured cosmic ray flux above E > 10^{18} eV. We show that relaxing the assumption of identical sources and using a power-law distribution of their maximal energy allows one to explain the observed UHECR spectrum with the injection 1/E^2 predicted by Fermi shock acceleration. We study possible ways to distinguish between these two cases with future experiments.
1 :  APC - UMR 7164 - AstroParticule et Cosmologie
APC - THEORIE
Physique/Astrophysique/Cosmologie et astrophysique extra-galactique

Planète et Univers/Astrophysique/Cosmologie et astrophysique extra-galactique

Planète et Univers/Astrophysique