Related papers: Neutron-loaded outflows in gamma-ray bursts
As it was recently shown by Derishev etal (1999), initial GRB ejecta are likely to contain comparable number of protons and neutrons. During acceleration process, and/or later, due to interaction with external medium, such ejecta are likely…
It has been suggested that non-relativistic outflows from quasars can naturally account for the missing component of the extragalactic $\gamma$-ray background and explain the cumulative neutrino background through pion decay in collisions…
We consider the effects of rapid pair creation by an intense pulse of gamma-rays propagating ahead of a relativistic shock. Side-scattered photons colliding with the main gamma-ray beam amplify the density of scattering charges. The…
We investigate a scenario of photons scattering by electrons within a relativistic outflow. The outflow is composed of discrete shells with different speeds. One shell emits radiation for a short duration. Some of this radiation is…
The various stages of baryonic gamma-ray burst afterglow blast waves are reviewed. These are responsible for the afterglow emission from which much of our understanding of gamma-ray bursts derives. Initially, the blast waves are confined to…
A model is proposed for gamma-ray bursts based upon a neutrino burst of about 10^52 ergs lasting a few seconds above a heated collapsing neutron star. This type of thermal neutrino burst is suggested by relativistic hydrodynamic studies of…
We study three processes that shape the nuclear composition of GRB fireballs: (1) neutronization in the central engine, (2) nucleosynthesis in the fireball as it expands and cools, and (3) spallation of nuclei in subsequent internal shocks.…
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…
We report on general relativistic hydrodynamic studies which indicate several new physical processes which may contribute to powering gamma-ray bursts in neutron star binaries. Relativistically driven compression, heating, and collapse of…
Quasar-driven outflows naturally account for the missing component of the extragalactic $\gamma$-ray background through neutral pion production in interactions between protons accelerated by the forward outflow shock and interstellar…
The internal/external synchrotron shock scenario has proved very successful in interpreting the key observations about gamma ray bursts. There still remains, however, some big uncertainties. The hottest issue concerns the nature of the…
(Abridged) We interpret gamma ray bursts as relativistic, electromagnetic explosions. Specifically, we propose that they are created when a rotating, relativistic, stellar-mass progenitor loses much of its rotational energy in the form of a…
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…
Recent observations suggest that long-duration gamma-ray bursts and their afterglows are produced by highly relativistic jets emitted in core-collapse explosions. As the jet makes its way out of the stellar mantle, a bow shock runs ahead…
We discuss the high energy neutrino emission from gamma-ray bursts resulting from the earliest generation (`population III') stars forming in the Universe, whose core collapses into a black hole. These gamma-ray bursts are expected to…
Protons accelerated to high energies in the relativistic shocks that generate gamma ray bursts photoproduce pions, and then neutrinos in situ. I show that ultra high energy neutrinos (> 10^19 eV) are produced during the burst and the…
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 early X-ray afterglow for a significant number of gamma-ray bursts detected by the Swift satellite is observed to have a phase of very slow flux decline with time ($F_\nu \propto t^{-\alpha}$ with $0.2 \lesssim \alpha \lesssim 0.8$) for…
The motions of comets and neutron stars have been integrated over five billion years in the Galactic potential to determine a gamma-ray burst distribution, presuming that bursts are the result of interactions between these two families of…
Supercriticality of the same kind as that in a nuclear pile can take place in high-energy astrophysical objects producing a number of impressive effects. For example, it could cause an explosive release of the energy of a cloud of…