相关论文: Accelerated Particles from Shocks Formed in Mergin…

We investigate binary mergers of galaxy clusters, the formation of shocks, and the resulting radio relics using three-dimensional simulations. The initial setup consists of two idealized spherical subclusters with a mass ratio below three,…

Models for the integrated relativistic electron population in clusters of galaxies are presented. The results depend on the history of electron acceleration in the cluster. If there is no present particle acceleration or other sources, then…

We investigate the heating of the quasi-free electrons in large rare gas clusters (N exceeding 10^5 atoms) by short laser pulses at moderate intensities (I~10^{15} Wcm^{-2}). We identify elastic large-angle backscattering of electrons at…

Acceleration of cosmic-ray electrons (CRe) in the intra-cluster-medium (ICM) is probed by radio observations that detect diffuse, Mpc-scale, synchrotron sources in a fraction of galaxy clusters. Giant radio halos are the most spectacular…

The non-thermal acceleration of electrons and ions at an oblique, non-relativistic shock is studied using large scale particle-in-cell (PIC) simulations in one spatial dimension. Physical parameters are selected to highlight the role of…

Cosmic-ray acceleration has been a long-standing mystery and despite more than a century of study, we still do not have a complete census of acceleration mechanisms. The collision of strong stellar winds in massive binary systems creates…

All galaxies without a radio-loud AGN follow a tight correlation between their global FIR and radio synchrotron luminosities, which is believed to be ultimately the result of the formation of massive stars. Two face-on colliding pairs of…

Possible formulations of the problem of cosmic rays acceleration in the interstellar galactic medium are considered with the use of fractional differential equations. The applied technique has been physically justified. A Fermi result has…

The acceleration of charged particles at astrophysical collisionless shock waves is one of the best studied processes for the energization of particles to ultrarelativistic energies, required by multifrequency observations in a variety of…

Stochastic acceleration of cosmic rays in second order Fermi processes is usually considered too slow to reach ultra-high energies, except in specific cases. In this paper we present the energy spectrum obtained from second order Fermi…

Recent radio observations support a picture for star formation where there is accretion of matter onto a central protostar with the ejection of molecular outflows that can affect the surrounding medium. The impact of a supersonic outflow on…

We investigate the interaction of nonthermal ions (protons and nuclei) accelerated in an ultrarelativistic blastwave with the pre-existing magnetic field of the medium into which the blastwave propagates. While particle acceleration…

Gamma-ray bursts are generally considered to be the result of internal shocks generated in an inhomogeneous relativistic outflow that arises from a fireball. In such shocks, the Fermi acceleration of protons is naturally expected to be at…

Magnetized turbulence and magnetic reconnection are often invoked to explain the nonthermal emission observed from a wide variety of astrophysical sources. By means of fully-kinetic 2D and 3D PIC simulations, we investigate the interplay…

Some clusters of galaxies in addition to thermal bremsstrahlung (TB), emit diffuse radiation from the intercluster medium (ICM) at radio, EUV and hard x-ray (HXR) ranges. The radio radiation is due to synchrotron by relativistic electrons,…

While dark matter self-interactions may solve several problems with structure formation, so far only the effects of two-body scatterings of dark matter particles have been considered. We show that, if a subdominant component of dark matter…

This review presents the fundamentals of the particle acceleration processes active in interstellar medium (ISM), which are essentially based on the so-called Fermi mechanism theory. More specifically, the review presents here in more…

Observational aspects of solar flares relevant to the acceleration process of electrons and protons are reviewed and it is shown that most of these observations can be explained by the interaction with flare plasma of a power law energy…

The most important evidences for non-thermal phenomena in galaxy clusters comes from the spectacular synchrotron radio emission diffused over Mpc scale observed in a growing number of massive clusters. A promising possibility to explain…

First-order Fermi acceleration processes at ultrarelativistic shocks are studied with Monte Carlo simulations. The accelerated particle spectra are derived by integrating the exact particle trajectories in a turbulent magnetic field near…