Related papers: Is magnetically dominated outflow required to expl…
Among the more than 1000 gamma-ray bursts observed by the Fermi Gamma-ray Space Telescope, a large fraction show narrow and hard spectra inconsistent with non-thermal emission, signifying optically thick emission from the photosphere.…
We review the recent observational results of the gamma-ray linear polarization of Gamma-Ray Bursts (GRBs), and discuss some theoretical implications for the prompt emission mechanism and the magnetic composition of GRB jets. We also report…
Recent analytical and numerical work argue that successful relativistic Fermi acceleration requires a weak magnetization of the unshocked plasma, all the more so at high Lorentz factors. The present paper tests this conclusion by computing…
In this paper, we revisit the scenario that an internal gradual magnetic dissipation takes place within the wind from a newborn millisecond magnetar can be responsible for gamma-ray burst production. We show that a combination of two…
Observations of the afterglows of gamma-ray bursts (GRBs) have revealed that they lie at cosmological distances, and so correspond to the release of an enormous amount of energy. The nature of the central engine that powers these events and…
We analyze a sample of\textit{ Swift} gamma-ray bursts (GRBs) with extended emissions in $\gamma$-rays and/or X-ray plateaus that may be driven by magnetars. Multi-wavelength data and multi-standards have been adopted to investigate the…
Gamma-ray Bursts (GRBs) are relativistic cosmological beacons of transient high energy radiation whose afterglows span the electromagnetic spectrum. Theoretical expectations of correlated neutrino and/or gravitational wave (GW) emission…
The Compactness Problem in GRBs has been resolved by invoking the Lorentz factors associated with the relativistic bulk motion. This scenario applies to GRBs where sufficient energy is converted to accelerate the ejected matter to…
We consider a model in which the ultra-relativistic jet in a gamma-ray burst (GRB) is cold and magnetically accelerated. We assume that the energy flux in the outflowing material is partially thermalized via internal shocks or a reverse…
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…
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…
It has been suggested that the prompt emission in gamma-ray bursts consists of several components giving rise to the observed spectral shape. Here we examine a sample of the 8 brightest, single pulsed {\it Fermi} bursts whose spectra are…
Gonz\'alez et al. (2003) have reported the discovery of an anomalous radiation component from ~ 1 -- 200 MeV in GRB 941017. This component varies independently of and contains >~ 3 times the energy found in the prompt ~ 50 keV -- 1 MeV…
Gamma-ray bursts (GRBs) are the most powerful explosions in the universe and probe physics under extreme conditions. GRBs divide into two classes, of short and long duration, thought to originate from different types of progenitor systems.…
Models for GRB outflows invoke turbulence in relativistically hot magnetized fluids. In order to investigate these conditions we have performed high-resolution three-dimensional numerical simulations of relativistic magneto-hydrodynamical…
We present a time-resolved spectral analysis of the bright, long GRB 061007 (z=1.261) using Swift BAT and Suzaku WAM data. We find that the prompt emission of GRB 061007 can be equally well explained by a photospheric component together…
For an unsteady baryonic gamma-ray burst (GRB) outflow, the fast and slow proton shells collide with each other and produce energetic soft gamma-ray emission. If the outflow has a significant neutron component, the ultra-relativistic…
Using GRB 991216 as a prototype, it is shown that the intensity substructures observed in what is generally called the "prompt emission" in gamma ray bursts (GRBs) do originate in the collision between the accelerated baryonic matter (ABM)…
The gamma-rays from gamma-ray bursts (GRBs) are believed to be produced by internal shocks driven by small timescale, ~1 ms, variation in the GRB outflows, and a pair-production spectral cutoff is generally expected around the GeV range.…
We present a model-independent way to characterise properties of the magnetic-field turbulence in the emitting regions of Gamma-Ray Burst afterglows. Our only assumption is that afterglows' synchrotron radiation is efficient. It turns out…