Related papers: Cosmic-ray propagation and interactions in the Gal…
The differential energy spectrum of cosmic rays from Cherenkov radiation measurements in EAS in the energy range of 10^15-10^20eV has been compared with an anomalous diffusion model for the particles in interstellar space having fractal…
Information on cosmic-ray (CR) composition comes from direct CR measurements while their distribution in the Galaxy is evaluated from observations of their associated diffuse emission in the range from radio to gamma rays. Even though the…
A brief review about the chemical composition of cosmic rays in the energy range 10^15 < E < 10^20 eV is given. While there is convincing evidence for an increasingly heavier composition above the knee, no clear picture has emerged at the…
Observations of light isotopes in cosmic rays provide information on their origin and propagation in the Galaxy. Using the data collected by AMS-01 in the STS- 91 space mission, we compare the measurements on 1H, 2H, 3He and 4He with…
We revisit propagation of galactic cosmic rays (CRs) in light of recent advances in CR diffusion theory in realistic interstellar turbulence. We use a tested model of turbulence in which it has been shown that fast modes dominate scattering…
The propagation of ultra high energy cosmic rays in Galactic and extragalactic magnetic fields is investigated in the present paper. The motion of charged particles of different energies and chemical composition is simulated using different…
Gamma-ray bursts and ultra-high-energy cosmic rays provide an important testing ground for fundamental physics. A simple-minded analysis of some gamma-ray bursts would lead to a huge estimate of the overall energy emitted, and this…
The spectral data on the diffuse Galactic gamma-rays, at medium and high latitudes (|b| > 10) and energies of 1-100 GeV, recently published by the Fermi Collaboration are used to produce a novel study on the gamma-ray emissivity in the…
Gamma-ray Astronomy studies cosmic accelerators through their electromagnetic radiation in the energy range between ~100 MeV and ~100 TeV. The present most sensitive observations in this energy band are performed, from space, by the Large…
We propose that cosmic rays originate mainly in three sites, a) normal supernova explosions into the interstellar medium, b) supernova explosions into stellar winds, and c) hot spots of powerful radio galaxies. The proposal depends on an…
Cosmic rays (CRs) interact with the gas, the radiation field and the magnetic field in the Milky Way, producing diffuse emission from radio to gamma rays. Observations of this diffuse emission and comparison with detailed predictions are…
A critical discussion of our knowledge about extragalactic cosmic rays and magnetic fields is attempted. What do we know for sure? What are our prejudices? How do we confront our models with the observations? How can we assess the…
Cosmic ray astronomy attempts to identify and study the sources of ultrahigh energy cosmic rays. It is unique in its reliance on charged particles as the information carriers. While no discrete source of ultrahigh energy cosmic rays has…
Cosmic rays are relativistic particles that come to the Earth from outer space. Despite a great effort made in both experimental and theoretical research, their origin is still unknown. One of the main keys to understand their nature is the…
Ever since the discovery of Cosmic Rays (CRs), significant advancements have been made in modeling their propagation in the Galaxy and in the Heliosphere. However, propagation models suffer from degeneracy of many parameters. To complicate…
This paper summarizes recent developments in the study of the propagation of ultra-high energy cosmic ray protons or nuclei in the Universe, with emphasis on the consequences of energy losses and on the influence of extra-galactic magnetic…
Pulsars are factories of relativistic electrons and positrons that propagate away from the pulsar, permeating later our Galaxy. The acceleration and propagation of these particles are a matter of intense debate. In the last few years, we…
The propagation of cosmic iron nuclei with energies above 10^19 eV from their sources to the Galaxy is discussed by assuming that cosmic rays at ultra-high energies are of extragalactic origin. In extragalactic space, cosmic nuclei interact…
We study the large-scale distribution of the arrival directions of the highest energy cosmic rays observed by various experiments. Despite clearly insufficient statistics, we find a deficit of cosmic rays at energies higher than 10^{20} eV…
The detection of cosmic rays with energy around and in excess of $10^{20}$ eV raises many questions that future experiments will help answering to. I address here my view of some of these open issues, as they are now and as they might be…