Related papers: Investigating the Temporal Evolution of Gamma-Ray …
The hypothesis that ultra-high energy (>~ 10^19 eV) cosmic rays (UHECRs) are accelerated by gamma-ray burst (GRB) blast waves is assumed to be correct. Implications of this assumption are then derived for the external shock model of…
Gamma-ray bursts are still a puzzle. In particular, the central engine, the total energy and the very narrow distribution of peak energies challenge model builders. We consider here an extreme model of gamma-ray bursts based on highly red-…
We present the first special relativistic, axisymmetric hydrodynamic simulations of black hole-torus systems (approximating general relativistic gravity) as remnants of binary-neutron star (NS-NS) and neutron star-black hole (NS-BH)…
As the plausible central engine of gamma-ray bursts (GRBs), a black hole (BH) hyperaccretion disk should be in a state of neutrino-dominated accretion flow (NDAF) if the accretion rate is larger than the ignition rate of an NDAF. A rotating…
We present late-time radio and X-ray observations of the nearby sub-energetic Gamma-Ray Burst (GRB)100316D associated with supernova (SN) 2010bh. Our broad-band analysis constrains the explosion properties of GRB100316D to be intermediate…
A wide range of mechanisms have been proposed to supply the energy for gamma-ray bursts (GRB) at cosmological distances. It is a common misconception that some of these, notably NS-NS mergers, cannot meet the energy requirements suggested…
Long-duration gamma-ray bursts (GRBs) have been often considered as the natural evolution of some core-collapse supernovae (SNe). While GRBs with relativistic jets emit an electromagnetic signal, GRBs with mildly relativistic jets are…
Neutrino annihilation process on a hyperaccreting disk is one of the leading models to explain the generation of relativistic jets of gamma-ray bursts (GRBs). However, there is still uncertainty regarding the NAE of neutron star-accretion…
Black hole - neutron star (BHNS) and neutron star - neutron star (NSNS) binaries are among the favored candidates for the progenitors of the black hole - disk systems that may be the engines powering short-hard gamma ray bursts. After…
Merging of stellar-mass binary black holes (BBH) could take place within the accretion disk of active galactic nuclei (AGN). The resulting BH remnant is likely to accrete the disk gas at a super-Eddington rate, launching a fast,…
Neutron star mergers can form a hypermassive neutron star (HMNS) remnant, which may be the engine of a short gamma ray burst (SGRB) before it collapses to a black hole, possibly several hundred milliseconds after the merger. During the…
We review models of cosmological gamma-ray bursts (GRBs). The statistical and $\gamma$-ray transparency issues are summarized. Neutron-star and black-hole merger scenarios are described and estimates of merger rates are summarized. We…
We describe the results high resolution, hydrodynamic calculations of neutron star mergers. The model makes use of a new, nuclear equation of state, accounts for multi-flavour neutrino emission and solves the equations of hydrodynamics…
GRBs are the most energetic electromagnetic events in the Universe. Those whose typical duration is longer than a few seconds are known as long GRBs and shorter than a few seconds are short GRBs. It is widely accepted that these events are…
The observation of a gamma-ray burst (GRB) associated with a supernova (SN) coincides remarkably with the energy output from a binary system comprising a very massive carbon-oxygen (CO) core and an associated binary neutron star (NS) by the…
The last five years have seen growing challenges to the traditional paradigm of a core collapse supernova powered by the neutrino emission of a young proto-neutron star. Chief among these challenges are gamma-ray bursts (GRBs) and the…
A new model of gamma bursts (GB) generated by MACHO's in the form of noncompact dark matter halo objects (NO) is proposed. The model explain well the spherical symmetry, $log N - log S$ curve of GB absolutely identically to the well-known…
Compact-object binary mergers consisting of one neutron star and one black hole (NSBHs) have long been considered promising progenitors for gamma-ray bursts, whose central engine remains poorly understood. Using gravitational-wave…
Cosmological gamma ray bursts (GRBs) are thought to occur from violent hypercritical accretion onto stellar mass black holes, either following core collapse in massive stars or compact binary mergers. This dichotomy may be reflected in the…
We present numerical simulations of energetic flows propagating through the debris cloud of a binary neutron star (BNS) merger. Starting from the scale of the central engine, we use a moving-mesh hydrodynamics code to simulate the complete…