Related papers: The Pierre Auger Observatory and Physics Beyond th…

The topic of Lorentz invariance violation is a fundamental question in physics that has taken on particular interest in theoretical explorations of quantum gravity scenarios. I discuss various gamma-ray observations that give limits on…

In the past few years, cosmic-rays beyond the GZK cut-off ($E > 5 \times 10^{19}$ eV) have been detected by leading collaborations such as Pierre Auger Observatory. Such observations raise many questions as to how such energies can be…

The determination of the primary energy of extensive air showers using the fluorescence detection technique requires an estimation of the energy carried away by particles that do not deposit all their energy in the atmosphere. This…

Data collected so far by the Pierre Auger Observatory have enabled major advances in ultra-high energy cosmic ray physics and demonstrated that improved determination of masses of primary cosmic-ray particles, preferably on an…

The Auger project was designed to study the high-energy cosmic rays by measuring the properties of the showers produced in the atmosphere. The Southern Auger Observatory has taken data since January 2004 and is now completed. Results on…

If the dark matter of our galaxy is composed of nuggets of quarks or antiquarks in a colour superconducting phase there will be a small but non-zero flux of these objects through the Earth's atmosphere. A nugget of quark matter will deposit…

Ultra high energy particles arrive at Earth constantly. They provide a beam at energies higher than any man-made accelerator, but at a very low rate. Two large experiments, the Pierre Auger Observatory and the Telescope Array experiment,…

The Pierre Auger Observatory is designed to study cosmic rays of the highest energies ($>10^{19}$ eV). The ground array of the Observatory will consist of 1600 water Cherenkov detectors deployed over 3000 km^2. The remoteness and large…

Extensive air showers are the result of billions of particle reactions initiated by single cosmic rays at ultra-high energy. Their characteristics are sensitive both to the mass of the primary cosmic ray and to the fine details of hadronic…

Taking into account the Pierre Auger Observatory limits on the photon fraction among the highest energy cosmic rays, we show that the models based on the decay of super-heavy dark matter in the halo of our Galaxy are essentially excluded…

Detecting neutrinos and photons is crucial to identifying the sources of ultrahigh-energy cosmic rays (UHECRs), especially for transient sources. We focus on ultrahigh-energy gamma-ray emission from transient sources such as gamma-ray…

The southern Pierre Auger Observatory is presently under construction in Malargue, Mendoza, Argentina. It combines two complementary air shower observation techniques; the detection of particles at ground and the observation of associated…

Based on observations of the depth of shower maximum performed with the hybrid detector of the Auger Observatory, an upper limit on the cosmic-ray photon fraction of 26% (at 95% confidence level) is derived for primary energies above 10^19…

The Pierre Auger Observatory, located in La Pampa Amarilla, Argentina, has been continuously acquiring data since 2004. It comprises a surface detector array covering 3,000 km$^2$ and 27 fluorescence telescopes, designed to detect extensive…

The Pierre Auger Observatory has begun a major Upgrade of its already impressive capabilities, with an emphasis on improved mass composition determination using the surface detectors of the Observatory. Known as AugerPrime, the upgrade will…

Highlights from the Pierre Auger Observatory are presented. In particular there is a detailed discussion of of the cosmic ray energy spectrum from 0.3 EeV to 100 EeV and of the mass composition above 1 EeV.

The Pierre Auger Observatory detects ultra-high energy cosmic rays by implementing two complementary air-shower techniques. The combination of a large ground array and fluorescence detectors, known as the hybrid concept, means that a rich…

When searching for anisotropies in the arrival directions of Ultra High Energy Cosmic Rays, one must estimate the number of events expected in each direction of the sky in the case of a perfect isotropy. We present in this article a new…

With the Surface Detector array (SD) of the Pierre Auger Observatory we can detect neutrinos with energy between $10^{17}\,$eV and $10^{20}\,$eV from point-like sources across the sky, from close to the Southern Celestial Pole up to…

The Pierre Auger Observatory is a facility built to detect air showers produced by cosmic rays above 10^17 eV. During clear nights with a low illuminated moon fraction, the UV fluorescence light produced by air showers is recorded by…