Related papers: Compton Dragged Gamma--Ray Bursts associated with …
Thermal X-ray emission which is simultaneous with the prompt gamma-rays has been detected for the first time from a supernova connected with a gamma-ray burst (GRB), namely GRB060218/SN2006aj. It has been interpreted as arising from the…
A theory is proposed to explain with simplicity the basic observed properties of a Gamma Ray Burst (GRB). It employs a well-known result of Schwinger, that static electric fields in excess of a critical value are unstable to pair creation,…
A pedagogical derivation is presented of the ``fireball'' model of gamma-ray bursts, according to which the observable effects are due to the dissipation of the kinetic energy of a relativistically expanding wind, a ``fireball.'' The main…
If the emission of gamma-ray bursts were due to the synchrotron process in the standard internal shock scenario, then the typical observed spectrum should have a slope F(nu) \propto nu^{-1/2}, which strongly conflicts with the much harder…
We consider gamma-ray burst outflows with a substantial neutron component that are either dominated by thermal energy (fireballs) or by magnetic energy. In the latter case, we focus on the recently introduced `AC' model which relies on…
We propose a model in which prompt gamma emission of gamma-ray bursts is the synchrotron radiation of electron-positron plasma in the ordered magnetic field in the direct vicinity of horizon of a young black hole formed in the core collapse…
Whatever the ultimate energy source of gamma-ray bursts turns out to be, the resulting sequence of physical events is likely to lead to a fairly generic, almost unavoidable scenario: a relativistic fireball that dissipates its energy after…
The prompt gamma-ray emission in gamma-ray bursts is believed to be produced by internal shocks within a relativistic unsteady outflow. The recent detection of prompt optical emission accompanying the prompt gamma-ray emission appears to be…
We identify a novel physical mechanism that may be responsible for energy release in $\gamma$-ray bursts. Radial perturbations in the neutron core, induced by its collision with collapsing outer layers during the early stages of supernova…
Gamma-ray bursts are generally considered to be the result of internal shocks generated in an inhomogeneous relativistic outflow that arises from a fireball. In such shocks, the Fermi acceleration of protons is naturally expected to be at…
We propose that repeated photoexcitation/ionization of high Z atoms of highly relativistic flows by star light in dense stellar regions followed by emission of decay/recombination photons, which are beamed and boosted to gamma ray energies…
Despite that gamma-ray bursts is a phenomenon quite different from accreting compact objects, it could be that their hard X-ray emission is associated with a very similar mechanism of energy dissipation. In both cases, we could deal with…
The principal paradigm for the prompt emission of gamma-ray bursts invokes diffusive acceleration at shocks internal to the dynamic ultrarelativistic outflow. This paper explores expectations for burst emission spectra arising from shock…
Protons accelerated in the internal shocks of a long duration gamma ray burst can escape the fireball as cosmic rays by converting to neutrons. Hadronic interactions of these neutrons inside a stellar wind bubble created by the progenitor…
It is generally believed that cosmological Gamma Ray Bursts (GRBs) are produced by the deceleration of relativistic objects with Lorentz factor (Gamma) >~ 100. We study the possibility that some GRBs are produced along with relativistic…
We calculate the synchrotron self-Compton emission from internal shocks occurring in relativistic winds as a source of gamma-ray bursts, with allowance for self-absorption. For plausible model parameters most pulses within a Gamma-Ray Burst…
The relativistic outflows from gamma-ray bursts are now thought to be narrowly collimated into jets. After correcting for this jet geometry there is a remarkable constancy of both the energy radiated by the burst and the kinetic energy…
The phase-transition induced collapse of a neutron star to a more compact configuration (typically a ``strange'' star) and the subsequent core bounce is often invoked as a model for gamma-ray bursts. We present the results of numerical…
Data from the Swift satellite has enabled us for the first time to provide a complete picture of the gamma-ray burst emission mechanism and its relationship with the early afterglow emissions. We show that gamma-ray photons for two bursts,…
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…