Related papers: Recent results from the Pierre Auger Observatory
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…
Ultra-high-energy cosmic rays (UHECRs) are the highest energy messengers in the universe, with energies up to $10^{20}$ eV. Studies of astrophysical particles (nuclei, electrons, neutrinos and photons) at their highest observed energies…
The ultra-high-energy cosmic ray (UHECR) spectra measured by the Pierre Auger Observatory (Auger) and the Telescope Array (TA) agree very well below $10^{19.5}$ eV but differ significantly at higher energies. We show that these differences…
Ultra-high energy cosmic rays (UHECRs) have been studied with the data of the Pierre Auger Observatory for more than fifteen years. An essential feature of the Observatory is its hybrid design: UHECRs are detected through the observation of…
The Pierre Auger Observatory has associated a few ultra high energy cosmic rays with the direction of Centaurus A. This source has been deeply studied in radio, infrared, X-ray and $\gamma$-rays (MeV-TeV) because it is the nearest…
In this review we discuss the important progress made in recent years towards understanding the experimental data on cosmic rays with energies $\agt 10^{19}$ eV. We begin with a brief survey of the available data, including a description of…
We present a combined fit of a simple astrophysical model of UHECR sources to both the energy spectrum and mass composition data measured by the Pierre Auger Observatory. The fit has been performed for energies above 5 EeV, i.e. the region…
The present situation with regard to experimental data on ultra high-energy cosmic rays is briefly reviewed. Whilst detailed knowledge of the shape of the energy spectrum is still lacking, it is clear that events above 10^20 eV do exist.…
The Pierre Auger Southern Observatory in Argentina has begun taking data as it is being developed up to a final enclosed area of 3000 square kilometres. A key aspect of the project is to provide information on the origin of the highest…
We test for an anisotropy in the mass of arriving cosmic-ray primaries associated with the galactic plane. The sensitivity to primary mass is obtained through the depth of shower maximum, $X_{\rm max}$, extracted from hybrid events measured…
The starburst galaxies M82 and NGC253 have been proposed as the primary sources of cosmic rays with energies above $10^{18.7}$ eV. For energies $\agt 10^{20.3}$ eV the model predicts strong anisotropies. We calculate the probabilities that…
Ultra-High Energy Cosmic Rays (UHECRs) are charged particles of energies above $10^{18}$ eV that originate outside of the Galaxy. Because the flux of the UHECRs at Earth is very small, the only practical way of observing UHECRs is by…
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,…
We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm…
This paper reports on recent results from measurements of energy spectrum and nuclear composition of galactic cosmic rays performed with the IceCube Observatory at the South Pole in the energy range between about 300 TeV and 1 EeV.
The Fluorescence Detector of the Pierre Auger Observatory measures the atmospheric depth, $X_{max}$, where the longitudinal profile of the high energy air showers reaches its maximum. This is sensitive to the nuclear mass composition of the…
More than two years of fluorescence detector data collected in coincidence with at least one station of the surface detector array (``hybrid data'') are used to measure the flux and energy spectrum of cosmic rays above about 10$^{18}$ eV.…
Motivated by the detection of a significant dipole structure in the arrival directions of ultrahigh-energy cosmic rays above 8 EeV reported by the Pierre Auger Observatory (Auger), we search for a large-scale anisotropy using data collected…
The Pierre Auger Collaboration has provided a compelling indication for a possible correlation between the arrival directions of ultrahigh-energy cosmic rays and nearby starburst galaxies. Herein we show how the latest large-scale modeling…
The status of the observations of Ultra High Energy Cosmic Rays will be reviewed, focusing on the the latest results of HiRes and Auger observatories. A comprehensive analytical computation scheme to compute the expected UHECR spectrum on…