Related papers: Gamma-ray bursts: a Centauro's cry?
The observed afterglows of gamma ray bursts, in particular that of GRB 970228 six months later, seem to rule out relativistic fireballs and relativistic firecones driven by merger or accretion induced collapse of compact stellar objects in…
We propose a model to explain how a Gamma Rays Burst can take place days or years after a supernova explosion. Our model is based on the conversion of a pure hadronic star (neutron star) into a star made at least in part of deconfined quark…
Gamma-ray bursts are believed to result from the coalescence of binary neutron stars. However, the standard proposals for conversion of the gravitational energy to thermal energy have difficulties. We show that if the merger of the two…
To anyone who has read a scientific journal or even a newspaper in the last six months, it might appear that cosmic gamma-ray bursts hold no more mysteries: they are cosmological, and possibly the most powerful explosions in the Universe.…
Gamma-ray bursts are associated with catastrophic cosmic events. They appear when a new black hole, created after the explosion of a massive star or the merger of two compact stars, quickly accretes the matter around it and ejects a…
Gamma-ray bursts (GRBs) are the most luminous electromagnetic burst in the Universe. They occur when a rapidly rotating massive star collapses or a binary neutron star merges. These events leave a newborn central compact object, either a…
The central engine which powers the Gamma-Ray Burst (GRB) fireball, produces neutrinos in the energy range of about 5-20 MeV. Fractions of these neutrinos may propagate through the fireball which is far away from the central engine. We have…
We investigate the fate of very compact, sudden energy depositions that may lie at the origin of gamma-ray bursts. Following on from the work of Cavallo and Rees (1978), we take account of the much higher energies now believed to be…
We indicate a possible mechanism of generating gamma ray bursts. They are generated by a collision between an axionic boson star and a neutron star. The axionic boson star can dissipates its whole energy $10^{50}$ erg in the magnetized…
The successful discovery of X-ray, optical and radio afterglows of gamma-ray bursts has significantly helped our understanding of these sources, and made possible the identification of host galaxies at cosmological distances. The energy…
We discuss the possibility that the sources for gamma ray bursts are hot neutron stars at cosmological distance scales. The temperature of such stars would be $T \sim 1 \MeV$. Such hot stars can produce an electromagnetic blast wave…
As it is well-known that the hydrodinamic collapse of the massive star iron core should lead to the production of a hot neutron star. The assumption is made that the thermonuclear burning of the envelope matter, accreting onto the hot…
Core collapse of massive stars resulting in a relativistic fireball jet which breaks through the stellar envelope is a widely discussed scenario for gamma-ray burst production. For very extended or slow rotating stars, the fireball may be…
Fireballs are an essential part of any cosmological $\gamma$-ray burst. We drive here a stability criterion for fireballs and show that fireballs are Rayleigh-Taylor unstable in any region in which the entropy decreases outward. The…
Most gamma-ray bursts are made during the deaths of massive stars. Here the environmental circumstances, stellar evolutionary paths, and explosion physics that might produce the bursts are reviewed. Neither of the two leading models -…
Gamma-ray bursts are flashes of high-energy radiation lasting from a fraction of a second to several hours. Military satellites made the first detections of GRBs in the late 1960s. The $\gamma$-ray emission forms from shocks in a…
We propose that gamma ray bursts (GRBs) are produced by a shower of heavy blobs running into circumstellar material at highly relativistic speeds. The gamma ray emission is produced in the shocks these bullets drive into the surrounding…
We suggest that the collapsing core of a massive rotating star may fragment to produce two or more compact objects. Their coalescence under gravitational radiation gives the resulting black hole or neutron star a significant kick velocity,…
Leading models for the "central engine" of long, soft gamma-ray bursts (GRBs) are briefly reviewed with emphasis on the collapsar model. Growing evidence supports the hypothesis that GRBs are a supernova-like phenomenon occurring in star…
Binary neutron stars merger (NS$^2$M) at cosmological distances is probably the only $\gamma$-ray bursts model based on an independently observed phenomenon which is known to be taking place at a comparable rate. We describe this model, its…