Related papers: How Pulses in Short Gamma-Ray Bursts Constrain HMX…
One of the possible origins of short gamma-ray bursts (SGRBs) is merging of compact binaries, and the effect of large kick velocity is a signature that can be used as an observational test for this hypothesis. Intracluster SGRBs that…
Some short gamma-ray bursts (SGRBs) are thought to be caused by the mergers of binary neutron stars which may sometimes produce massive neutron star remnants capable of producing extragalactic fast radio bursts (FRBs). We conducted a deep…
Evolution of the rate density of cosmological gamma-ray bursts (GRBs) is calculated and compared to the BATSE brightness distribution in the context of binary neutron-star mergers as the source of GRBs, taking account of the realistic star…
We review our current understanding of the progenitors of both long and short duration gamma-ray bursts (GRBs). Constraints can be derived from multiple directions, and we use three distinct strands; i) direct observations of GRBs and their…
Cosmological gamma-ray bursts (GRBs) are probably powered by systems harboring a rotating black hole. These may result from hypernovae or black hole-neutron star coalescence. We identify short/long bursts with hyper- and suspended-accretion…
We have carried out a detailed study of the morphology of gamma-ray bursts (GRBs) with time duration less than 100 ms that includes: (1) a fast-Fourier spectrum analysis, (2) a comparison with the Stern analysis of longer bursts, (3) an…
Short gamma-ray bursts (GRBs) are believed to be produced by relativistic jets from mergers of neutron-stars (NS) or neutron-stars and black-holes (BH). If the Lorentz-factors $\Gamma$ of jets from compact-stellar-mergers follow a similar…
It is now generally accepted that long-duration gamma ray bursts (GRBs) are due to the collapse of massive rotating stars. The precise collapse process itself, however, is not yet fully understood. Strong winds, outbursts, and intense…
Previous studies of the evolution of gamma-ray burst spectra have generally relied on fitting sequences of spectra. These studies usually were confined to bright bursts and often lacked sufficient temporal resolution. We have developed…
The temporal properties of a sample of 498 bright gamma-ray bursts (GRBs) with durations between 0.05 s and 674 s were analysed. The large range in duration (T90) is accompanied by a similarly large range in the median values of the pulse…
The first detection of a binary neutron star merger, GW170817, and an associated short gamma-ray burst confirmed that neutron star mergers are responsible for at least some of these bursts. The prompt gamma ray emission from these events is…
A long-standing paradigm in astrophysics is that collisions- or mergers- of two neutron stars (NSs) form highly relativistic and collimated outflows (jets) powering gamma-ray bursts (GRBs) of short (< 2 s) duration. However, the…
We report evidence from the 3B Catalogue that long ($T_{90} > 10$ s) and short ($T_{90} < 10$ s) gamma-ray bursts represent distinct source populations. Their spatial distributions are significantly different, with long bursts having…
One of the most dramatic possible consequences of stellar rotation is its influence on stellar death, particularly of massive stars. If the angular momentum of the iron core when it collapses is such as to produce a neutron star with a…
Short-duration gamma-ray bursts (SGRBs) are widely believed to be powered by the mergers of compact binaries, such as binary neutron stars or possibly neutron star-black hole binaries. Though the prospect of detecting SGRBs with…
Gravitational waves (GW) can be emitted from coalescing neutron star (NS) and black hole-neutron star (BH-NS) binaries, which are thought to be the sources of short hard gamma ray bursts (SHBs). The gamma ray fireballs seem to be beamed…
The recent detections of the $\sim10$-s long $\gamma$-ray bursts (GRBs) 211211A and 230307A followed by softer temporally extended emission (EE) and kilonovae, point to a new GRB class. Using state-of-the-art first-principles simulations,…
Gamma Ray Bursts as recent GRB990123 and GRB990510 are observed to occur in cosmic volumes with a corresponding output reaching, for isotropic explosions, energies as large as two solar masses annihilation. These energies are underestimated…
Gamma-ray bursts (GRBs), the most energetic transients in the Universe, are traditionally classified into long-duration ($T_{90}>2$ s) and short-duration ($T_{90}<2$ s) events, associated with the core collapse of massive stars (Type II)…
A significant fraction of the Long Gamma-ray Bursts (LGRBs) in the Swift sample have a plateau phase showing evidence of ongoing energy injection. We suggest that many Short Gamma-ray Bursts (SGRBs) detected by the Swift satellite also show…