Related papers: The Anisotropy Search Program For the Pierre Auger…
Ultra-high-energy cosmic rays are known to be mainly of extragalactic origin, and their propagation is limited by energy losses, so their arrival directions are expected to correlate with the large-scale structure of the local Universe. In…
The Pierre Auger Observatory is the largest operating cosmic ray observatory ever built. Calorimetric measurements of extensive air showers induced by cosmic rays are performed with a fluorescence detector. Thus, one of the main challenges…
We study the arrival directions of 69 ultra-high energy cosmic rays (UHECRs) observed at the Pierre Auger Observatory (PAO) with energies exceeding 55 EeV. We investigate whether the UHECRs exhibit the anisotropy signal expected if the…
Current experiments collecting high statistics in ultra-high energy cosmic rays (UHECRs) are opening a new window on the universe facing the possibility to perform UHECR astronomy. Here we discuss a large scale structure (LSS) model for the…
We explore the potential of a future, ultra-high energy cosmic ray (UHECR) experiment, that is able to overcome the limitation of low statistics, to detect anisotropy in the arrival directions of UHECRs. We concentrate on the lower energy…
The Pierre Auger Observatory, a hybrid detector for the study of ultra-high energy cosmic rays (UHECRs), is now approaching completion. After describing Auger present status and performance, with an emphasis on the advantages provided by…
Several explanations for the existence of Ultra High Energy Cosmic Rays (UHECR) invoke the idea that they originate from the decay of massive particles created in the reheating following inflation. It has been suggested that the decay…
The sources of ultra-high energy cosmic rays are not yet known. However, the discovery of anisotropic cosmic rays above 57x10^18 eV by the Pierre Auger Observatory suggests that a direct source detection may soon be possible. The…
The fluorescence-detection techniques of cosmic-ray air-shower experiments require precise knowledge of atmospheric properties to reconstruct air-shower energies. Up to now, the atmosphere in desert-like areas was assumed to be stable…
The search of a clustering signal in the arrival directions of ultra-high-energy cosmic rays (UHECRs) is a standard method to assess the level of anisotropy of the data sets under investigation. Here, we first show how to quantify the…
We present results of elaborate four-dimensional simulations of the propagation of ultra-high-energy cosmic rays (UHECR), which are based on a realistic astrophysical scenario. The distribution of the arrival directions of the UHECR is…
Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with $E \geq 6 \cdot 10^{19}$ eV by analyzing…
Measurements of air showers are accumulating at an increasing rate while construction proceeds at the Pierre Auger Observatory. Although the southern site is only half complete, the cumulative exposure is already similar to those achieved…
The Pierre Auger Observatory is the largest air-shower detector in the world, offering unparalleled exposure to photons with energies above $5 \times 10^{16}$ eV. Since the start of data collection almost two decades ago, numerous searches…
Many models for ultra-high energy cosmic rays postulate exotic scenarios to explain the sources or the nature of these particles. A characteristic feature of these models is the prediction of a significant flux of photons at ultra-high…
Since 2021, the Open Data Portal has provided access to the Pierre Auger Observatory's data for both the scientific community and the general public. The data release process has been in place since the Observatory's foundation. It…
The Pierre Auger Collaboration discovered, in a solid angle of radius about 18\degree, a local group of cosmic rays having energies in the region E0 \geq 5.5\times1019 eV and coming from the region of the Gen A radio galaxy, whose galactic…
We develop a method to study the anisotropy of a cosmic-ray angular distribution, using both the right ascension and the declination of the arrival directions. It generalises the full-sky coverage method of Sommers (2001) to partial-sky…
Using data from the SUGAR and the AGASA experiments taken during a 10 yr period with nearly uniform exposure to the entire sky, we search for large-scale anisotropy patterns in the arrival directions of cosmic rays with energies > 10^{19.6}…
The Pierre Auger Observatory has been designed to study the highest-energy cosmic rays in nature (E > 10^{18.5} eV). The determination of their arrival direction, energy and composition is performed by the analysis of the atmospheric…