Related papers: Galactic calibration and its long-term stability f…
The arrival directions of ultra-high-energy cosmic rays appear to be approximately isotropically distributed over the whole sky, but the last-generation UHECR detector arrays, the Pierre Auger Observatory (Auger) and the Telescope Array…
The Pierre Auger Observatory in Malargue, Argentina, is designed to study the origin of ultrahigh energy cosmic rays with energies above 10^18 eV. The energy calibration of the detector is based on a system of four air fluorescence…
The standard method to estimate the mass of a cosmic ray is the measurement of the atmospheric depth of the shower maximum ($X_\text{max}$). This depth is strongly correlated with the mass of the primary because it depends on the…
The question of whether intelligent life exists elsewhere is one of the fundamental unknowns about our Universe. Over the past decade more than 200 extra-solar planets have been discovered, providing new urgency for addressing this question…
The Gaia-ESO survey (GES) is now in its fifth and last year of observations, and has already produced tens of thousands of high-quality spectra of stars in all Milky Way components. This paper presents the strategy behind the selection of…
The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world's largest cosmic ray observatory. The objectives of the Observatory are to probe the origin and characteristics of cosmic rays above $10^{17}$ eV…
HERA is a highly-redundant transit interferometer with 14\,m-diameter parabolic dish elements. We exploit the fact that the Galactic centre transits through the main beam of the telescope to attempt a conventional self-calibration approach…
Experiments designed to detect ultra-high energy (UHE) neutrinos using radio techniques are also capable of detecting the radio signals from cosmic-ray (CR) induced air showers. These CR signals are important both as a background and as a…
Searches for ultra-high energy ($E_\nu \geq 10$ PeV) cosmogenic and astrophysical neutrinos (UHENs) have been conducted by several experiments over the last two decades. The Askaryan Radio Array (ARA), located near the geographical South…
The Pierre Auger Observatory is a hybrid detector designed to observe and study ultra-high-energy particles of extraterrestrial origin. With its 27 fluorescence telescopes and over 1600 autonomously operating water-Cherenkov detectors…
We present a novel approach for assessing the muon content of air showers with large zenith angles on a combined analysis of their radio emission and particle footprint. We use the radiation energy reconstructed by the Auger Engineering…
We describe the experimental setup and the results of RAuger, a small radio-antenna array, consisting of three fully autonomous and self-triggered radio-detection stations, installed close to the center of the Surface Detector (SD) of the…
The Pierre Auger Observatory (PAO) and Telescope Array (TA) collaborations report significant differences in the observed energy spectra of ultra-high-energy cosmic rays (UHECRs) above 30~EeV. In this work we present a joint fit of TA and…
We investigate the effects of solar activity on the Auger Engineering Radio Array (AERA) data collected over 10 years. We report the observation of Solar Radio Burst signals in AERA data associated with intense solar flares accompanied by…
The ARIANNA hexagonal radio array (HRA) is an experiment in its pilot phase designed to detect cosmogenic neutrinos of energies above 10^16 eV. The most neutrino-like background stems from the radio emission of air showers. This article…
The correlation between the directions of optically-detected AGNs within 75 Mpc and the arrival directions of cosmic rays above 57 EeV detected by the Auger collaboration up to August 2007 is examined using uniform-exposure plots and a form…
We present the first results from the COLA (Compact Objects in Low-power AGN) project which aims to determine the relationship between one facet of AGN activity, the compact radio core, with star formation in the circumnuclear region of the…
The Askaryan Radio Array Station 1 (A1), the first among five autonomous stations deployed for the ARA experiment at the South Pole, is a unique ultra-high energy neutrino (UHEN) detector based on the Askaryan effect that uses Antarctic ice…
The Pierre Auger Cosmic-Ray Observatory uses the earth's atmosphere as a calorimeter to measure extensive air-showers created by particles of astrophysical origin. Some of these particles carry joules of energy. At these extreme energies,…
A wide-frequency radio study of Active Galactic Nuclei (AGN) is crucial to evaluate the intervening radiative mechanisms responsible for the observed emission and relate them with the underlying accretion physics. We present wide frequency…