A closer look at the spectrum and small scale anisotropies of UHECRs

Abstract

We present results of numerical simulations of the propagation of ultra high energy cosmic rays (UHECRs) over cosmological distances, aimed at quantifying the statistical significance of the highest energy data on the spectrum and small scale anisotropies as detected by the AGASA experiment. We assess the significance of the lack of a GZK feature and its compatibility with the reported small scale anisotropies. Assuming that UHECRs are protons from extragalactic sources, we find that the small scale anisotropies are incompatible with the reported spectrum at a probability level of $2\times 10^{-5}$. Our analysis of the AGASA results shows the power of combining spectrum and small scale anisotropy data in future high statistics experiments, such as Auger.

arXiv comment13 pages, 7 figures, submitted to JCAP

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Cited by in corpus (10)

• On astrophysical solution to ultra high energy cosmic rays
• Searching for a Correlation Between Cosmic-Ray Sources Above 10^{19} eV and Large-Scale Structure
• Cosmic Rays and the Search for a Lorentz Invariance Violation
• Astroparticle Physics: Puzzles and Discoveries
• Clustering properties of ultrahigh energy cosmic rays and the search for their astrophysical sources
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• Pierre Auger Data, Photons, and Top-Down Cosmic Ray Models
• Small Scale Anisotropy Predictions for the Auger Observatory
• On Anisotropy of Ultra-High Energy Cosmic-Rays