Measurement of the Energy Spectrum of Cosmic Rays with the Pierre Auger Observatory

Abstract

The flux of cosmic rays has been measured with unprecedented precision at the Pierre Auger Observatory. We report on the recent update of the all-sky flux of cosmic rays above 31017eV obtained by combining four independent high-quality data sets collected for more than 10 years, with a total exposure exceeding 50,000 km2sr yr. These measurements are based on data from the surface detector arrays (divided into two sets according to the shower zenith angle), from a nested, denser, detector array, and hybrid events measured simultaneously with both the fluorescence detector and the surface detector. The spectral features are presented in detail and the systematic uncertainties are addressed.