Related papers: Electromagnetic (versus fireball) model of GRBs
We compare two possible scenarios for the producing of high level of polarization within the prompt emission of a GRB: synchrotron emission from a relativistic jet with a uniform (in space and time) magnetic field and synchrotron emission…
We show that the excellent optical and gamma-ray data available for GRB 080319B rule out the internal shock model for the prompt emission. The data instead point to a model in which the observed radiation was produced close to the…
The afterglows of gamma-ray bursts are non-thermal electron synchrotron emissions from relativistic shocks. The origin of strong magnetic field in the emission region remains elusive, and two field amplification mechanisms via the plasma…
A temporal analysis has been performed on a sample of 100 bright gamma-ray bursts (GRBs) with T90<2s from the BATSE current catalog. The GRBs were denoised using a median filter and subjected to an automated pulse selection algorithm as an…
The cannonball model (CB) of gamma ray bursts (GRBs) is incredibly more successful than the standard blast-wave models (SM) of GRBs, which suffer from profound inadequacies and limited predictive power. The CB model is falsifiable in its…
Gamma-ray burst GRB 140430A was detected by the Swift satellite and observed promptly with the imaging polarimeter RINGO3 mounted on the Liverpool Telescope, with observations beginning while the prompt $\gamma$-ray emission was still…
The standard model of Gamma-Ray Bursts afterglows is based on synchrotron radiation from a blast wave produced when the relativistic ejecta encounters the surrounding medium. We reanalyze the refreshed shock scenario, in which slower…
Over the past few decades impressive progress has been made in the field of photon polarimetry, especially in the hard X-ray and soft gamma-ray energy regime. Measurements of the linear degree of polarization for some of the most energetic…
We have performed a systematic study of Gamma-Ray Bursts (GRBs), which have various values in the peak energy of the ${\nu}F_{\nu}$ spectrum of the prompt emission, $E_{{\rm peak}}$, observed by \textsl{Swift}/BAT and \textsl{Fermi}/GBM,…
The prompt emission of most gamma-ray bursts (GRBs) typically exhibits a non-thermal Band component. The synchrotron radiation in the popular internal shock model is generally put forward to explain such a non-thermal component. However,…
Several GRB afterglow light curves deviate strongly from the power law decay observed in most bursts. We show that these variations can be accounted for by including refreshed shocks in the standard fireball model previously used to…
Recent rapid advances in the observations of Gamma Ray Bursts (GRBs) lend much confidence to the cosmological fireball (FB) model: there is now compelling evidence that the radiation is emitted by a relativistic shock where a high speed…
We report on the polarization measure, obtained with IBIS on board INTEGRAL, of the prompt emission of GRB 061122. Over an 8 s interval containing the brightest part of the Gamma-Ray Burst we put a lower limit on its polarization fraction…
The prompt optical emission that arrives with gamma-rays from a cosmic gamma-ray burst (GRB) is a signature of the engine powering the burst, the properties of the ultra-relativistic ejecta of the explosion, and the ejecta's interactions…
The degree to which gamma ray bursts are collimated is now the dominant uncertainty in their energy requirements and event rates. In this review I begin with the reasons for studying GRB collimation, then discuss existing tests for…
According to the internal-external shocks model for $\gamma $-ray bursts (GRBs), the GRB is produced by internal shocks within a relativistic flow while the afterglow is produced by external shocks with the ISM. We explore the early…
Photospheric (thermal) emission is inherent to the gamma-ray burst (GRB) "fireball" model. We show here, that inclusion of this component in the analysis of the GRB prompt emission phase naturally explains some of the prompt GRB spectra…
We report the polarization measurement in prompt $\gamma$-ray emission of GRB 100826A with the Gamma-Ray Burst Polarimeter (GAP) aboard the small solar power sail demonstrator IKAROS. We detected the firm change of polarization angle (PA)…
We study the dynamics of relativistic electromagnetic explosions as a possible mechanism for the production of Gamma-Ray Bursts. We propose that a rotating relativistic stellar-mass progenitor loses much of its spin energy in the form of an…
The multi-window observations, including the light curve and the evolutions of the spectral peak energy ($E_p$), the polarization degree (PD) and the polarization angle (PA), are used to infer the model parameters to predict the…