H. Cook

TL;DR: In this article, the Pierre Auger Collaboration has reported evidence for anisotropies in the arrival directions of cosmic rays with energies larger thanEth = 55 EeV and showed that there is a correlation above the isotropic expectation with nearby active galaxies and the largest excess is in a celestial region around the position of the radio galaxy Cen A.

TL;DR: The measurement of the depth of maximum, X{max}, of the longitudinal development of air showers induced by cosmic rays is described and the interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

TL;DR: In this article, the authors reported a measurement of the flux of cosmic rays with unprecedented precision and statistics using the Pierre Auger Observatory based on fluorescence observations in coincidence with at least one surface detector.

TL;DR: In this paper, anisotropy was measured by the fraction of arrival directions that are less than 3.1 degrees from the position of an active galactic nucleus within 75 Mpc (using the Veron-Cetty and Veron 12th catalog).

TL;DR: A measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV is reported, derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory.