Using data collected at the Pierre Auger Observatory during the past 3.7 years, we
demonstrated a correlation between the arrival directions of cosmic rays with energy above …

An efficient scheme for one-dimensional extensive air shower simulation and its
implementation in the program conex are presented. Explicit Monte Carlo simulation of the …

The Pierre Auger Observatory is designed to unveil the nature and the origins of the highest
energy cosmic rays. The large and geographically dispersed collaboration of physicists and …

The energies of cosmic rays, fully ionized charged nuclei, extend over a wide range up to
1020 eV. A particularly interesting energy region spans from 1014 to 1018 eV, where the all …

To determine the size of an extensive air shower it is not necessary to have knowledge of
the function that describes the fall-off of signal size from the shower core (the lateral …

The fluorescence detection of ultra high energy (≳ 1018eV) cosmic rays requires a detailed
knowledge of the fluorescence light emission from nitrogen molecules, which are excited by …

An upper limit of 16%(at 95% cl) is derived for the photon fraction in cosmic rays with
energies greater than 1019eV, based on observations of the depth of shower maximum …

The Pierre Auger Observatory (PAO) has measured the spectrum and composition of the
ultrahigh energy cosmic rays with unprecedented precision. We use these measurements to …

Gamma-ray bursts, which are among the most violent events in the Universe, are one of the
few viable candidates to produce ultra high-energy cosmic rays. Recently, observations …

TeV γ-rays may provide significant information about high energy astrophysical accelerators.
Such γ-rays can result from the photo-de-excitation of PeV nuclei after their parents have …