Related papers: Electron acceleration at pulsar wind termination s…
We present a Chandra Director's Discretionary Time observation of PSR J1119-6127 and its compact X-ray pulsar wind nebula (PWN) obtained on 27 October 2016, three months after the Fermi and Swift detection of millisecond bursts in hard…
X-ray observations of several kiloparsec-scale extragalactic jets favour a synchrotron origin. The short cooling times of the emitting electrons requires distributed acceleration of electrons up to sub-PeV energies. In a previous paper, we…
We study the physics of electron acceleration at collisionless shocks that move through a plasma containing large-scale magnetic fluctuations. We numerically integrate the trajectories of a large number of electrons, which are treated as…
We numerically explore electron acceleration and coronal heating by dissipative electric fields. Electrons are traced in linear force-free magnetic fields extrapolated from SOHO/MDI magnetograms, endowed with anomalous resistivity ($\eta$)…
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…
A full particle simulation study is carried out on the electron acceleration at a collisionless, relatively low Alfven Mach number (M_A=5), perpendicular shock. Recent self-consistent hybrid shock simulations have demonstrated that the…
Observational data require a rich variety of mechanisms to accelerate fast particles in astrophysical environments operating under different conditions. The mechanisms discussed in the literature include varying magnetic fields in compact…
Pulsars, or more generally rotation powered neutron stars, are excellent factories of antimatter in the Galaxy, in the form of pairs of electrons and positrons. Electrons are initially extracted from the surface of the star by the intense…
In this paper, we discuss the results of a new particle pusher in realistic ultra-strong electromagnetic fields as those encountered around rotating neutron stars. After presenting results of this algorithm in simple fields and comparing…
Where and how flares efficiently accelerate charged particles remains an unresolved question. Recent studies revealed that a "magnetic bottle" structure, which forms near the bottom of a large-scale reconnection current sheet above the…
The outflows from gamma ray bursts, active galactic nuclei and relativistic jets in general interact with the surrounding media through collisionless shocks. With three dimensional relativistic particle-in-cell simulations we investigate…
We consider the acceleration of charged particles in relativistic shearing flows, with Lorentz factor up to $\Gamma_0 \sim 20$. We present numerical solutions to the particle transport equation and compare these with results from analytical…
We analyze electron flux maps based on RHESSI hard X-ray imaging spectroscopy data for a number of extended coronal loop flare events. For each event, we determine the variation of the characteristic loop length $L$ with electron energy…
Using test particle simulations we study electron acceleration at collisionless shocks with a two-component model turbulent magnetic field with slab component including dissipation range. We investigate the importance of shock normal angle…
High-energy particles were recorded by near-Earth spacecraft and ground-based neutron monitors (NMs) on 2012 May 17. This event was the first ground level enhancement (GLE) of solar cycle 24. In this study, we try to identify the…
Pulsars with high spin-down power produce relativistic winds radiating a fraction of the power in the range from radio to gamma-rays in the pulsar wind nebulae (PWNe). The rest of the power is dissipated in the interactions of the PWNe with…
We study an acceleration of electrons and positrons in the relativistic magnetic field reconnection using a 2.5-D particle-in-cell electromagnetic relativistic code. We consider the model with two current sheets and periodic boundary…
Nonlinear electromagnetic waves with superluminal phase velocity can propagate in the winds around isolated pulsars, and around some pulsars in binary systems. Using a short-wavelength approximation, we find and analyze an integrable system…
Charged particles can be accelerated to high energies by collisionless shock waves in astrophysical environments, such as supernova remnants. By interacting with the magnetized ambient medium, these shocks can transfer energy to particles.…
We analyse the damping by radiation reaction and by Compton drag of strong, superluminal electromagnetic waves in the context of pulsar winds. The associated radiation signature is found by estimating the efficiency and the characteristic…