相关论文: Isotopic composition of cosmic-ray sources
We use the GALPROP model for cosmic-ray (CR) propagation to obtain our best prediction of the Galactic component of gamma rays, and show that away from the Galactic plane it gives an accurate prediction of the observed EGRET intensities. On…
The GALPROP model for cosmic-ray (CR) propagation produces explicit predictions for the angular distribution of Galactic diffuse gamma rays. We compare our current models with EGRET spectra for various regions of the sky. This allows a…
We are constructing a model which aims to reproduce observational data of many kinds related to cosmic-ray origin and propagation: direct measurements of nuclei, antiprotons, electrons and positrons, gamma-rays, and synchrotron radiation.…
Recent observations have revealed that several cosmic ray (CR) sources themselves exhibit pronounced double power-law features in their radiation spectra. Combined with the phenomenon of two-component structure in the observed CR energy…
Analyses of TeV-PeV cosmic ray (CR) diffusion around their sources usually assume either isotropic diffusion or anisotropic diffusion due to the regular Galactic magnetic field. We show that none of them are adequate on distances smaller…
We predict the arrival direction distribution of cosmic rays including their deflection in the Galactic magnetic field, for several combinations of source and composition hypotheses: the sources are hard X-ray AGNs or uniformly sample the…
After the discovery of Fermi Bubbles and the excess of gamma-ray emission, the Galactic Centre has received increasing attention with the aim to understand its role in the origin and acceleration of primary cosmic rays (CRs). Based on a…
We calculate the diffusion coefficients of charged cosmic rays (CR) propagating in regular and turbulent magnetic fields. If the magnetic field is dominated by an isotropic turbulent component, we find that CRs reside too long in the…
We use the GALPROP cosmic ray (CR) framework to model the Galactic CR distributions and associated non-thermal diffuse emissions up to PeV energies. We consider ensembles of discrete, finite lifetime CR sources, e.g.\ supernova remnants…
The chemical composition of the highest-energy cosmic rays, namely the atomic number $Z$ of rays with energies $E\gtrsim40~\mathrm{EeV}$, remains to date largely unknown. Some information on the composition can be inferred from the…
Cosmic-ray (CR) leptons produce radio synchrotron radiation by gyrating in interstellar magnetic fields (B-field). Details of B-fields, CR electron distributions and propagation are still uncertain. We present developments in our modelling…
The nuclei fraction in cosmic rays (CR) far exceeds the fraction of other CR species, such as antiprotons, electrons, and positrons. Thus the majority of information obtained from CR studies is based on interpretation of isotopic abundances…
In this paper, we study the propagation of cosmic-ray nuclei and protons. We emphasize the influence of the source composition on the expected spectrum and composition on Earth as well as on the phenomenology of the transition from Galactic…
We calculate the energy spectra and mass composition of cosmic rays in energy region 1 - 10^8 GeV/particle under the assumption that cosmic rays propagation in the Galaxy is described by anomalous diffusion equation. Our results and…
The composition of Galactic Cosmic Rays (GCR) presents strong similarities to the standard (cosmic) composition, but also noticeable differences, the most important being the high isotopic ratio of Ne22/Ne20 which is about 5 times higher in…
Cosmic Rays (CRs) include Galactic Cosmic Rays (GCRs) and Anomalous Cosmic Rays (ACRs). The CR flux data of protons and heavy-ions observed with spacecraft are often seriously contaminated by Solar Energetic Particle (SEP) events. In this…
Galactic cosmic rays are a ubiquitous source of ionisation of the interstellar gas, competing with UV and X-ray photons as well as natural radioactivity in determining the fractional abundance of electrons, ions and charged dust grains in…
A very interesting puzzle about the origin of electron and positron cosmic rays is deduced from the latests experimental results. We model the propagation of such cosmic rays in terms of a successfully tested two--zone propagation model.…
We present a complete phenomenological model accounting for the evolution of the cosmic-ray spectrum and composition with energy, based on the available data over the entire spectrum. We show that there is no need to postulate any…
The chemical composition of ultra-high energy cosmic rays is a key question in particle astrophysics. The measured composition, inferred from the elongation rates of cosmic ray showers, looks in general very different from the initial…