Related papers: High energy cosmic rays, gamma rays and neutrinos …
The extragalactic sources of ultra-high-energy (E > 4x10^19 eV) cosmic rays that make a small contribution to the flux of particles recorded by ground-based arrays are discussed. We show that cosmic rays from such sources can produce a…
The possibility of estimating the mass composition of primary cosmic rays above the knee of its energy spectrum through the study of high energy gamma rays, muons and neutrinos produced in the interactions of cosmic rays with the solar…
Active Galactic Nuclei (AGN) are remarkable astronomical sources emitting over the whole electromagnetic spectrum, with different bands providing unique windows on distinct sub-structures and their related physics. AGN come in a large…
The origin of highest energy cosmic rays (UHECR) is yet unknown. In order to understand their propagation we determine the probability that an ultrahigh energy (above 5\cdot 10^{19} eV) proton created at a distance r with energy E arrives…
The ANTARES collaboration propose to observe High Energy Cosmic Neutrinos using a Deep Sea Cherenkov detector. The sky survey with high energy neutrinos is complementary to the observations with photons. It is expected that this will shed a…
Gamma-Ray Bursts (GRBs) are expected to efficiently accelerate protons up to relativistic energies. High-energy photons can originate from decay of neutral pions produced by the interaction of these protons with the medium surrounding the…
The origin of the ultra high energy cosmic rays (UHECR) with energies above E > 1017eV, is still unknown. The discovery of their sources will reveal the engines of the most energetic astrophysical accelerators in the universe. This is a…
The propagation of high-energy cosmic rays in the Galaxy is investigated. Solutions of a diffusion model are combined with numerically calculated trajectories of particles. The resulting escape path length and interaction path length are…
Active Galactic Nuclei (AGN) are multiwavelength emitters. To have any hope of understanding them, or even to determine their energy output, we must observe them with many telescopes. I will review what we have learned from broad-band…
We report on the search for ultra-high-energy neutrinos from the prompt emission of gamma-ray bursts (GRBs) using Surface Detector (SD) data from Phase I of the Pierre Auger Observatory (2004-2021). A total of 570 GRBs occur within the most…
The correlation between the pointing direction of ultra high energy cosmic rays and AGN observed by the Pierre Auger Collaboration is explained in the framework of acceleration process in AGN. This acceleration process is produced by a…
The ANTARES project aims at the construction of a neutrino telescope 2500 m below the surface of the Mediterranean sea, close to the southern French coast. The apparatus will consist of a 3D array of photomultiplier tubes, which detects the…
Despite many efforts to find a reasonable explanation, the origin of the "knee" in the cosmic ray spectrum at energy around 10**15.5 eV remains mysterious. In this letter we suggest that the "knee" may be due to a GZK-like effect of cosmic…
Recent progress in cosmic ray physics covering the energy range from about 10^{14} eV to 10^{19} eV is reviewed. The most prominent features of the energy spectrum are the so called `knee' at E ~ 3 * 10^{15} eV and the `ankle' at few…
Gamma-ray bursts have the potential to produce the particle energies (up to $10^{21}$ eV) and the energy budget ($10^{44} \rm{erg yr^{-1} Mpc^{-3}}$) to accommodate the spectrum of the highest energy cosmic rays; on the other hand, there is…
IceCube is a cubic-kilometer Cherenkov telescope operating at the South Pole. In 2013 IceCube discovered high-energy astrophysical neutrinos and has more recently found compelling evidence for a flaring blazar being a source of high-energy…
Gamma-ray bursts (GRBs) are sources of energetic, highly variable fluxes of gamma rays, which demonstrates that they are powerful particle accelerators. Besides relativistic electrons, GRBs should also accelerate high-energy hadrons, some…
Studies of the cosmic ray energy spectrum at the highest energies with the Pierre Auger Observatory
We present the general properties of the Active Galactic Nuclei (AGNs) and discuss the origin and structure of jets that are associated to a fraction of these objects. We then we address the problems of particle acceleration at highly…
An overview of the multi-messenger capabilities of the Pierre Auger Observatory is presented. The techniques and performance of searching for Ultra-High Energy neutrinos, photons and neutrons are described. Some of the most relevant results…