相关论文: Self-confinement of low-energy cosmic rays around …
In the 1960s, the remnants of supernova explosions (SNRs) were indicated as a possible source of galactic cosmic rays through the Diffusive Shock Acceleration (DSA) mechanism. Since then, the observation of gamma-ray emission from…
The supernova remnant (SNR) G51.26+0.11 was recently discovered and little is known about its properties and environment. Using data from the \emph{Fermi} Large Area Telescope we study the GeV emission seen in the direction of G51.26+0.11…
Recent observations of high energy cosmic-ray electrons by the Fermi-LAT and the HESS experiments between $20$ GeV and $5$ TeV have found that the energy spectrum closely follow a broken power-law with a break at around $1$ TeV. On the…
Supernova remnants (SNRs) in the Galaxy are an important source of energy injection into the interstellar medium, and also of cosmic rays. Currently there are 294 known SNRs in the Galaxy, and their distribution with Galactocentric radius…
A theory of cosmic-ray transport in multi-phase diffusive media is developed, with the specific application to cases in which the cosmic-ray diffusion coefficient has large spatial fluctuations that may be inherently multi-scale. We…
Context. Galactic cosmic rays are widely assumed to arise from diffusive shock acceleration, specifically at shocks in supernova remnants (SNRs). These shocks expand in a complex environment, particularly in the core-collapse scenario as…
Recent results from the HESS gamma ray telescope have shown the presence of both a diffuse, extended, flux of gamma rays above ~0.4 TeV and discrete sources in and near the Galactic Centre. Here, we put forward a possible explanation in…
Diffusive shock acceleration by the shockwaves in supernova remnants (SNRs) is widely accepted as the dominant source for Galactic cosmic rays. However, it is unknown what determines the maximum energy of accelerated particles. The…
The existence of nearby discrete cosmic-ray sources can lead to many interesting effects on the observed properties of cosmic rays. Recent measurements of cosmic rays with the CALET and the DAMPE experiments have revealed a bump-like new…
Analyses of the X-ray data of the five young shell-type supernova remnants Cas A, Kepler, Tycho, SN 1006, and RCW 86 suggest that some of the X-ray emission of these sources is non-thermal. This non-thermal emission is qualitatively…
We analyze the results of recent measurements of Galactic cosmic ray (GCRs) energy spectra and the spectra of nonthermal emission from supernova remnants (SNRs) in order to determine their consistency with GCR origin in SNRs. It is shown…
The search for the origin of cosmic rays is as active as ever, mainly driven by new insights provided by recent pieces of observation. Much effort is being channelled in putting the so called supernova paradigm for the origin of galactic…
If cosmic rays with energies <100 TeV originate in the galaxy and are accelerated in shock waves in shell-type supernova remnants (SNRs), gamma-rays will be produced as the result of proton and electron interactions with the local…
We derive constraints that must be satisfied by the sources of ~10^{15} to ~10^{18} eV cosmic rays, under the assumption that the sources are Galactic. We show that while these constraints are not satisfied by ordinary supernovae (SNe),…
Super-bubbles are shells in the interstellar medium produced by the simultaneous explosions of many supernova remnants. The solutions of the mathematical diffusion and of the Fourier expansion in 1D, 2D and 3D were deduced in order to…
We consider diffusive shock acceleration in supernova remnants throughout their evolution including a radiative stage. It is found that a more efficient acceleration and fast exit of particles at the radiative stage results in the hardening…
The origin and nature of ultrahigh energy cosmic rays with energies above $10^{20}\,$eV is a puzzle for the physics and astrophysics of cosmic rays which is still unresolved. In this paper, I report on an extensive study on the propagation…
I constrain a possible supernova origin for gamma-ray bursts by modeling the dynamical interaction between a relativistic jet and a stellar envelope surrounding it. The delay in observer's time introduced by the jet traversing the envelope…
The growth of magneto-hydrodynamic fluctuations relevant to cosmic ray confinement in and near their sources, and the effects of local plasma conditions is revisited. We consider cases where cosmic rays penetrate a medium which may contain…
Our Galaxy is the largest nuclear interaction experiment which we know, because of the interaction between cosmic ray particles and the interstellar material. Cosmic rays are particles, which have been accelerated in the Galaxy or in…