Related papers: The termination shock in a striped pulsar wind
The processes leading to the exceptionally hard radio spectra of pulsar-wind nebulae (PWNe) are not yet understood. Radio photon spectral indices among $29$ PWNe from the literature show an approximately normal, $\alpha=0.2\pm0.2$…
We investigate the acceleration of light particles in perpendicular shocks for plasmas consisting of a mixture of leptonic and hadronic particles. Starting from the full set of conservation equations for the mixed plasma constituents, we…
Reconnection of alternating magnetic fields is an important energy transformation mechanism in Poynting dominated outflows. We show that the reconnection is facilitated by the Kruskal-Schwarzschild instability of current sheets separating…
We study in detail the electromagnetic fields and the Poynting flux in the case of a uniformly accelerated charge, in order to examine whether such a charge does `emit' radiation, especially in view of the widely accepted fact that there is…
When the pressure of particles accelerated at shock waves is no longer negligible compared to the kinetic pressure of the gas, the linear theory of diffusive shock acceleration breaks down. This is expected in particular when the shock…
The effect of compressibility in charged particle energization by magnetohydrodynamic (MHD) fields is studiedin the context of test particle simulations. This problem is relevant to the solar wind and the solar corona due to the…
The available data of single X-ray pulsars, their wind nebulae, and the SNRs which are connected to some of these sources are analysed. It is shown that electric field intensity of neutron stars tears off charged particles from the surface…
Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g.,Buneman, Weibel and other two-stream instabilities) created in collisionless shocks are responsible for particle…
The available data on isolated X-ray pulsars, their wind nebulae, and the supernova remnants which are connected to some of these sources are analyzed. It is shown that electric fields of neutron stars tear off charged particles from the…
We present the study of SOL2015-03-15 M1.2 flare, revealing acceleration of electrons and plasma heating in the sheared twisted magnetic structure in the polarity inversion line (PIL). The scope is to make the analysis of nonthermal…
Context: The strong electric fields associated with magnetic reconnection in solar flares are a plausible mechanism to accelerate populations of high energy, non-thermal particles. One such reconnection scenario occurs at a 3D magnetic null…
The theory of first order Fermi acceleration at shocks assumes that particles diffuse due to scattering off slow-moving magnetic irregularities. However, cosmic rays are closely tied to magnetic field lines, and the transport process,…
We present evidence that relativistic shocks propagating in unmagnetized plasmas can self-consistently accelerate particles. We use long-term two-dimensional particle-in-cell simulations to study the well-developed shock structure in…
Switchbacks (rotations of the magnetic field) are observed on the Parker Solar Probe. Their evolution, content, and plasma effects are studied in this paper. The solar wind does not receive a net acceleration from switchbacks that it…
Questions regarding energy dissipation in astrophysical jets are open to date, despite of numerous attempts to limit the diversity of models. Some of the most popular models assume that energy is transferred to particles via internal…
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…
Shocks in astrophysical transients are key sites of particle acceleration. If the shock upstream is optically thick, radiation smoothens the velocity discontinuity at the shock (radiation-mediated shocks). However, in mildly magnetized…
Synchrotron radiation detected from relativistic astrophysical objects such as pulsar-wind nebulae and {jets from active galactic nuclei} depends on the magnetic fields and the distribution functions of energetic electrons in these systems.…
Collisionless shock waves, found in supernova remnants, interstellar, stellar, and planetary environments, and laboratories, are one of nature's most powerful particle accelerators. This study combines in situ satellite measurements with…
Nanoflares, which are consequences of braids in tangled magnetic fields, are an important candidate to heat the solar corona to million degrees. However, their observational evidence is sparse and many of their observational characteristics…