Related papers: Cosmic ray acceleration at oblique shocks
Recent results by space borne experiments took cosmic ray data to a precision level. These new results are able to challenge the conventional scenario for cosmic ray acceleration and propagation in the Milky Way. In these contributions,…
A review of theoretical results on cosmic ray first-order Fermi acceleration at relativistic shock waves is presented, with recent results substantially changing the existing knowledge on these processes. In particular one can not expect…
Particle acceleration occurs on a range of scales from AU in the heliosphere to Mpc in clusters of galaxies and to energies ranging from MeV to EeV. A number of acceleration processes have been proposed, but diffusive shock acceleration…
The early acceleration of protons and electrons in the nonrelativistic collisionless shocks with three obliquities are investigated through 1D particle-in-cell simulations. In the simulations, the charged particles possessing a velocity of…
Precise measurements of galactic cosmic rays revealed a significant difference between the rigidity spectral indices of protons and helium ions. This finding is a notable contrast to the commonly accepted theoretical prediction that…
This article presents a description of a cosmic rays diffusive propagationmodel of a close point-like flash lamp like source and an approximation ofexperimentally observed spectral irregularity with this model. We show thatthis spectral…
Cosmological hydrodynamic simulations have demonstrated that shock waves could be produced in the intergalactic medium by supersonic flow motions during the course of hierarchical clustering of the large-scale-structure in the Universe.…
Using an eigenfunction expansion to solve the transport equation, complemented by Monte-Carlo simulations, we show that ultrarelativistic shocks can be effective particle accelerators even when they fail to produce large amplitude…
The cosmic ray energy distributions contain spectral features, that is narrow energy regions where the slope of the spectrum changes rapidly. The identification and study of these features is of great importance to understand the…
Under nonuniform convection, the distribution of diffusive particles can exhibit dipole and quadrupole anisotropy induced by the fluid inertial and shear force, respectively. These convection-related anisotropies, unlike the Compton-Getting…
The recent detection of high energy gamma-rays coming from supernova remnants and active galactic nuclei has revived interest in the diffusive shock acceleration of electrons. In the present paper we examine the basis of the so-called…
Nonlinear model of diffusive shock acceleration is used for investigation of the particle acceleration in old supernova remnants W28 and W44. We modeled the hydrodynamical evolution of the remnants, shock modification and streaming…
The ratio between secondary and primary cosmic ray particles is the main source of information about cosmic ray propagation in the Galaxy. Primary cosmic rays are thought to be accelerated mainly in Supernova Remnant (SNR) shocks and then…
The probability that a particle, crossing the shock along a given direction, be reflected backwards along another direction, was shown to be the key element in determining the spectrum of non--thermal particles accelerated via Fermi…
Particle acceleration at astrophysical shocks may be very efficient if magnetic scattering is self-generated by the same particles. This nonlinear process adds to the nonlinear modification of the shock due to the dynamical reaction of the…
We consider the diffusive shock acceleration in interstellar bubbles created by powerful stellar winds of supernova progenitors. Under the moderate stellar wind magnetization the bubbles are filled by the strongly magnetized low density…
Supernovae remnant shock waves could be at the origin of cosmic rays up to energies in excess of the knee ($E\simeq3\cdot 10^{15} $eV) if the magnetic field is efficiently amplified by the streaming of accelerated particles in the shock…
The cosmic ray (CR) energy spectra measured with ATIC, CREAM and PAMELA showed that there is remarkable hardening for rigidity of several hundred GV. We propose that this hardening is due to the superposition of spectra from a population of…
The analytical theory of diffusive cosmic ray acceleration at parallel stationary shock waves with magnetostatic turbulence is generalized to arbitrary shock speeds $V_s=\beta_1c$, including in particular relativistic speeds. This is…
Context. Radio relics in galaxy clusters are known to be good laboratories for verification of the applicability of the diffusive shock acceleration (DSA) model in its canonical version. The need for such verification stems from the…