We report a study of the distributions of the depth of maximum, X max, of extensive air-
shower profiles with energies above 1 0 17.8 eV as observed with the fluorescence …

Cosmic rays are atomic nuclei arriving from outer space that reach the highest energies
observed in nature. Clues to their origin come from studying the distribution of their arrival …

We present the first hybrid measurement of the average muon number in air showers at
ultrahigh energies, initiated by cosmic rays with zenith angles between 62° and 80°. The …

We report a measurement of the energy spectrum of cosmic rays for energies above 2.5× 10
18 eV based on 215,030 events recorded with zenith angles below 60°. A key feature of the …

We present a combined fit of a simple astrophysical model of UHECR sources to both the
energy spectrum and mass composition data measured by the Pierre Auger Observatory …

SEARCHES FOR ANISOTROPIES IN THE ARRIVAL DIRECTIONS OF THE HIGHEST
ENERGY COSMIC RAYS DETECTED BY THE PIERRE AUGER OBSERVATORY …

A new analysis of the data set from the Pierre Auger Observatory provides evidence for
anisotropy in the arrival directions of ultra-high-energy cosmic rays on an intermediate …

Abstract The Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) is designed to
accurately observe ultra-high-energy cosmic rays (UHECRs) and cosmic neutrinos from …

Neutrinos in the cosmic ray flux with energies near 1 EeV and above are detectable with the
Surface Detector array (SD) of the Pierre Auger Observatory. We report here on searches …

The Pierre Auger Observatory has begun a major Upgrade of its already impressive
capabilities, with an emphasis on improved mass composition determination using the …