Related papers: Close Binary Progenitors of Long Gamma Ray Bursts
We present our numerical results of two-dimensional hydrodynamic (HD) simulations and magnetohydrodynamic (MHD) simulations of the collapse of rotating massive stars in light of the collapsar model of gamma-ray bursts (GRBs). Pushed by…
We construct a simple but self-consistent collapsar model for gamma-ray bursts (GRBs) and SNe associated with GRBs (GRB-SNe).Our model includes a black hole, an accretion disk, and the envelope surrounding the central system.The evolutions…
The gamma-ray burst (GRB) 060218 has ~ 10^5 times lower luminosity than typical long GRBs, and is associated with a supernova (SN). The radio afterglow displays no jet break, so that this burst might arise from a mildly-relativistic…
We calculate new evolutionary models of rotating primordial very massive stars, with initial mass from $100\,M_{\odot}$ to $200\,M_{\odot}$, for two values of the initial metallicity ${Z=0}$ and ${Z=0.0002}$. For the first time in this mass…
In this paper we survey the theory of wind accretion in high mass X-ray binaries hosting a magnetic neutron star and a supergiant companion. We concentrate on the different types of interaction between the inflowing wind matter and the…
Likely progenitors for the GRBs (gamma-ray bursts) are the mergers of compact objects or the explosions of massive stars. These two cases have distinctive environments for the GRB afterglow: the compact object explosions occur in the ISM…
The central engine of gamma-ray bursts (GRBs) is believed to be a hot and dense disk with hyperaccretion onto a few solar-mass black hole. We investigate where the magnetorotational instability (MRI) actively operates in the hyperaccretion…
Recently, a kilonova-associated gamma-ray burst (GRB 211211A), whose light curve consists of a precursor ($\sim$0.2 s), a hard spiky emission ($\sim$10 s), and a soft long extended emission ($\sim$40 s), has attracted great attention.…
We present hydrodynamical models of circumstellar medium (CSM) of long gamma-ray burst (GRB) progenitor candidates. These are massive stars that have lost a large amount of mass in the form of stellar wind during their evolution. There are…
In this work we estimate the accretion-disk mass in the specific scenario of binary-neutron-star-merger with current observational data. Assuming that the outflows of short Gamma-ray Bursts (GRBs) are driven via neutrino-antineutrino…
The mechanism behind the launching of gamma-ray-burst (GRB) jets remains debated resulting in large uncertainty over the jet composition. Both magnetohydrodynamical and neutrino annihilation models have been proposed for the energy…
We present a new way of looking at the very long term evolution of GRBs in which the disk of material surrounding the putative black hole powering the GRB jet modulates the mass flow, and hence the efficacy of the process that extracts…
Precursor emission has been observed in a non-negligible fraction of gamma-ray bursts.The time gap between the precursor and the main burst extends in some case up to hundreds of seconds, such as in GRB041219A, GRB050820A and GRB060124.…
The plateau in the duration distribution of long Gamma-Ray Bursts (LGRBs) provides a direct observational evidence for the Collapsar model. The plateau reflects the fact that the observed duration satisfies: $T_{90} = t_{e}-t_{b}$ where…
Gamma-ray bursts (GRBs) are luminous and violent phenomena in the universe. Traditionally, long GRBs are expected to be produced by the collapse of massive stars and associated with supernovae. However, some low-redshift long GRBs have no…
The association between long gamma-ray bursts (LGRBs) and core-collapse supernovae (SNe) has been well established since the discovery of SN 1998bw, which was linked to the low-luminosity LGRB 980425. However, long-term monitoring of…
We present the first systematic study of X-ray flare candidates in short gamma-ray bursts (SGRBs) exploiting the large 6-year Swift database with the aim to constrain the physical nature of such fluctuations. We find that flare candidates…
BH-NS and BH-BH systems are among the most promising gravitational wave sources detectable by advanced LIGO/VIRGO and the Einstein Telescope. Although the rates of these systems may be above those of NS-NS mergers, BH-NS and BH-BH systems…
The merger of a neutron star binary may result in the formation of a rapidly-spinning magnetar. The magnetar can potentially survive for seconds or longer as a supramassive neutron star before collapsing to a black hole if, indeed, it…
Long-duration gamma-ray bursts (GRBs) are thought to come from the core-collapse of Wolf-Rayet stars. Whereas their stellar masses $M_*$ have a rather narrow distribution, the population of GRBs is very diverse, with gamma-ray luminosities…