Related papers: Coherent Electromagnetic Emission from Relativisti…
In the standard scenario of the fireball model of gamma-ray bursts(GRBs), the huge initial energy release produces a relativistic blast wave expanding into the external medium and a reverse shock moving into and heating the fireball ejecta.…
The dominant radiation mechanism that produces the prompt emission in gamma-ray bursts (GRBs) remains a major open question. Spectral information alone has proven insufficient in elucidating its nature. Time-resolved linear polarization has…
Fast radio bursts (FRBs) are millisecond radio pulses with extremely high bright temperature. Their physical origin is still a mystery. The discovery of FRB 20020428 supports the idea that at least a portion of FRBs is generated by…
Relativistic collisionless shocks are associated with efficient particle acceleration when propagating into weakly magnetized homogeneous media; as the magnetization increases, particle acceleration becomes suppressed. We demonstrate that…
We point out that the already existing literature on relativistic collisionless MHD shocks show that the parameter sigma= upstream proper magnetic energy density/upstream rest mass energy density, plays an important role in determining the…
It is shown that an ultrarelativistic shock with the Lorentz factor of order of tens or higher propagating in a moderately dense interstellar medium (density above $\sim 1000 $ cm$^{-3}$) undergoes a fast dramatic transformation into a…
Recently, a fast radio burst (FRB)-like event is found to be associated with a Galactic magnetar, SGR 1935+2154, accompanied by an X-ray burst. We find this radio burst challenges the typical emission mechanisms involving magnetars, which…
Common models of blazars and gamma-ray bursts assume that the plasma underlying the ob- served phenomenology is magnetized to some extent. Within this context, radiative signatures of dissipation of kinetic and conversion of magnetic energy…
When a gravitational shockwave hits a magnetar it creates perturbations of the magnetar magnetic field in a form of a transition radiation. We argue that this radiation can be a novel candidate to explain the origin of fast radio bursts…
Relativistic strongly magnetized winds outflowing from fast-rotating compact objects like millisecond pulsars with surface magnetic fields of $\sim 10^{15}-10^{16}$ G are plausible sources of cosmological $\gamma$-ray bursts. In such winds,…
We present detailed calculations of the prompt spectrum of gamma-ray bursts (GRBs) predicted within the fireball model framework, where emission is due to internal shocks in an expanding relativistic wind. Our time dependent numerical model…
The principal paradigm for gamma-ray bursts (GRBs) suggests that the prompt transient gamma-ray signal arises from multiple shocks internal to the relativistic expansion. This paper explores how GRB prompt emission spectra can constrain…
It is widely accepted that the prompt transient signal in the 10 keV - 10 GeV band from gamma-ray bursts (GRBs) arises from multiple shocks internal to the ultra-relativistic expansion. The detailed understanding of the dissipation and…
Fast radio bursts (FRBs) are mysterious radio transients whose physical origin is still unknown. Within a few astronomical units near an FRB source, the electric field of the electromagnetic wave is so large that the electron oscillation…
The generation of turbulence at magnetized shocks and its subsequent interaction with the latter is a key question of plasma- and high-energy astrophysics. This paper presents two-dimensional magnetohydrodynamic simulations of a fast shock…
The strong variability of magnetic central engines of AGN and GRBs may result in highly intermittent strongly magnetized relativistic outflows. We find a new magnetic acceleration mechanism for such impulsive flows that can be much more…
Generation of terahertz electromagnetic radiation due to coalescence of upper-hybrid waves in the long-wavelength region of strong plasma turbulence driven by a high-current relativistic electron beam in a magnetized plasma is investigated.…
Fast radio bursts (FRBs) are millisecond radio signals from cosmological distances. As they propagate, FRBs can interact with ambient photons and initiate a quantum cascade that can limit the electric field strength. This paper examines…
Among the models used to explain the prompt emission of gamma-ray bursts (GRBs), internal shocks is a leading one. Its most basic ingredient is a collision between two cold shells of different Lorentz factors in an ultra-relativistic…
Fast radio bursts (FRBs) are observed to be highly polarized. Most have high linear polarization but a small fraction show significant circular polarization. We systematically investigate a variety of polarization mechanisms of FRBs within…