Related papers: Dynamical Model of an Expanding Shell
An explosively generated shockwave with time-dependent radius $R(t)$ is characterized by a phase in which the shocked gas becomes radiative with an effective adiabatic index $\gamma \simeq 1$. Using the result that the post-shock gas is…
In present study I examine the capability of diffusive shock acceleration mechanism to explain existing data on radio emission from evolved large diameter shell-type adiabatic supernova remnants (SNRs). Time-dependent ''onion-shell'' model…
Understanding the evolution of a supernova remnant shell in time is fundamental. Such understanding is critical to build reliable models of the dynamics of the supernova remnant shell interaction with any pulsar wind nebula it might…
Gamma ray bursts (GRB) occur at random points in the sky at cosmological distances. The spectra evolve through X-ray, optical region to possibly radio frequency. Though there are some models, the origin and time evolution of GRB are not…
It has been suggested that relativistic blast waves may power the jets of AGN and gamma-ray bursts (GRB). We address the important issue how the kinetic energy of collimated blast waves is converted into radiation. It is shown that swept-up…
Supernova remnants (SNRs) are the outcome of supernovae (SNe, either core-collapse or thermonuclear). The remnant results from the interaction between the stellar ejecta and the ambient medium around the progenitor star. Young SNRs are…
Observations of both gamma-ray burst sources and certain classes of active galaxy indicate the presence of relativistic shock waves and require the production of high energy particles to explain their emission. In this paper we review the…
We calculate the spectrum of blast wave models of gamma-ray burst sources, for various assumptions about the magnetic field density and the relativistic particle acceleration efficiency. For a range of physically plausible models we find…
We calculate both analytically and numerically the evolution of a highly relativistic fireball through the stages of free expansion and coasting, and determine the dependence of the thermodynamic and radiation variables in the comoving and…
The evolution of the radio emission of shell-type Supernova remnants (SNRs) is modeled within the framework of the simple and commonly used assumptions that the mechanism of diffusive shock acceleration (DSA) is responsible for generating…
Gamma Ray Bursts (GRBs) are notorious for their diversity. Yet, they have a series of common features. The typical energy of their $\gamma$ rays is a fraction of an MeV. The energy distributions are well described by a ``Band spectrum'',…
The one-dimensional flight of a fast electron flux in plasma is investigated taking into account generation and absorption of plasma waves. The transition from the kinetic description to the gas dynamics is made. The closed set of gas…
We simulate the dynamics of the interaction between relativistically expanding spherically symmetric shells using a 1-dimensional hydrodynamic code and calculate spectra and light-curves arising from such collisions by integrating the…
Shell-type supernova remnants (SNRs) exhibit correlations between radio surface brightness, SNR diameter, and ambient medium density. We investigate these correlations, to extract useful information about the typical evolutionary stage of…
Methods for estimation of different reference times which appear in the description of transition of a strong adiabatic shock into the radiative era are reviewed. The need for consideration of an additional transition subphase in between…
We present analytical and numerical studies of models of supernova-remnant (SNR) blast waves expanding into uniform media and interacting with a denser cavity wall, in one spatial dimension. We predict the nonthermal emission from such…
The temporal evolution of the spectral break in the time resolved spectral energy density of the broad band afterglow of gamma ray bursts (GRBs) 091127 and 080319B was shown recently to be inconsistent with that expected for the cooling…
(Abridged) We present the results of three dimensional calculations for the MHD evolution of an adiabatic supernova remnant in both a uniform and turbulent interstellar medium using the RIEMANN framework of Balsara. In the uniform case,…
This paper reports on the results of a numerical investigation designed to address how the initially anisotropic appearance of a GRB remnant is modified by the character of the circumburst medium and by the possible presence of an…
We study the stochastic electron acceleration by fast mode waves in the turbulent downstream of weakly magnetized collisionless astrophysical shocks. The acceleration is most efficient in a dissipative layer, and the model characteristics…