Related papers: Proton acceleration in colliding stellar wind bina…
Massive colliding wind binary stars serve as laboratories for the study of strong-shock physics. In these systems fundamental flow parameters (velocities, densities, directions) are often well known, and photon fields important for Compton…
Synchrotron radiation of ultra-relativistic particles accelerated in a pulsar wind nebula may dominate its spectrum up to gamma-ray energies. Because of the short cooling time of the gamma-ray emitting electrons, the gamma-ray emission zone…
We present calculations of the spatial and spectral distribution of the radio emission from a wide WR+OB colliding-wind binary system based on high-resolution hydrodynamical simulations and solutions to the radiative transfer equation. We…
Non-thermal emission from relativistic electrons gives insight into the strength and morphology of intra-cluster magnetic fields, as well as providing powerful tracers of structure formation shocks. Emission caused by Cosmic Ray (CR)…
Cosmic Ray (CR) acceleration still challenges the researchers. Fast particles may be accelerated in astrophysical environments by a variety of processes. Acceleration in magnetic reconnection sites in particular, has lately attracted the…
We demonstrate a scheme for enhanced proton acceleration from near-critical-density targets by splitting a laser pulse into a linearly and a circularly polarized laser pulse. The combination of two laser pulses generates a shock wave as…
Supernova explosions into predecessor stellar winds can lead to particle acceleration, which we suggest can explain most of the observed cosmic rays of the nuclei of Helium and heavier elements, from GeV in particle energies up to near $3…
Plasma processes close to SNR shocks result in the amplification of magnetic fields and in the acceleration of electrons, injecting them into the diffusive acceleration mechanism. The acceleration of electrons and the B field amplification…
Pulsar Wind Nebulae are the astrophysical sources that host the most relativistic shocks in Nature and the only Galactic sources in which we have direct evidence of PeV particles. These facts make them very interesting from the point of…
A well-known paradigm about the origin of Galactic cosmic rays (CRs) is that these high-energy particles are accelerated in the process of diffusive shock acceleration (DSA) at collisionless shocks (at least up to the so-called "knee"energy…
The origin of cosmic rays in our Galaxy remains a subject of active debate. While supernova remnant shocks are often invoked as the sites of acceleration, it is now widely accepted that the difficulties of such sources in reaching PeV…
The powerful wind-wind collision in massive star binaries creates a region of high temperature plasma and accelerates particles to relativistic energies. I briefly summarize the hydrodynamics of the wind-wind interaction and the…
Context. We have presented a numerical model for the non-thermal emission of gamma-ray binaries in a pulsar-wind driven scenario. Aims. We apply this model to one of the best-observed gamma-ray binaries, the LS 5039 system. Methods. The…
Dispersive Alfven waves (DAWs) offer, an alternative to magnetic reconnection, opportunity to accelerate solar flare particles. We study the effect of DAW polarisation, L-, R-, circular and elliptical, in different regimes inertial and…
Recent reports claiming association of the massive star binary system $\gamma^2 $Velorum (WR 11) with a high-energy $\gamma$-ray source observed by \textit{Fermi}-LAT contrast the so-far exclusive role of $\eta$ Carinae as the hitherto only…
The colliding-wind region in binary systems made of massive stars allows us to investigate various aspects of shock physics, including particle acceleration. Particle accelerators of this kind are tagged as Particle-Accelerating…
We review the physics of relativistic shocks, which are often invoked as the sources of non-thermal particles in pulsar wind nebulae (PWNe), gamma-ray bursts (GRBs), and active galactic nuclei (AGN) jets, and as possible sources of…
We investigate the attainable maximum energy of particles accelerated in the core-collapse supernova remnant (SNR) shock propagating in the free wind region with the Parker-spiral magnetic field, current sheet, and the wind termination…
Many early-type stars are in binary systems. A number of them shows radio emissivity with periodic variability. This variability is associated with non-thermal synchrotron radiation emitted by relativistic electrons. The strong shocks…
In colliding-wind binaries, shocks accelerate a fraction of the electrons up to relativistic speeds. These electrons then emit synchrotron radiation at radio wavelengths. Whether or not we detect this radiation depends on the size of the…