Related papers: Gamma-ray Bursts
The collapsar model was proposed to explain the long-duration gamma-ray bursts (GRBs), while the short GRBs are associated with the mergers of compact objects. In the first case, mainly the energetics of the events is consistent with the…
Gamma-ray bursts (GRBs), associated with the collapse of massive stars or the collisions of compact objects, are the most luminous events in our universe. However, there is still much to learn about the nature of the relativistic jets…
The observations suggest that $\gamma$-ray bursts (GRBs) are produced by jets of relativistic cannonballs (CBs), emitted in supernova (SN) explosions. The CBs, reheated by their collision with the SN shell, emit radiation and Doppler-boost…
Lasting anywhere from a few milliseconds to several minutes, GRBs shine hundreds of times brighter than a typical supernova, making them briefly the brightest source of cosmic gamma-ray photons in the observable Universe. This thesis…
Gamma-Ray Burst (GRB) explosions from the first generation of stars offer an exciting opportunity to probe the epoch of reionization. Clues about how and when the intergalactic medium was ionized can be read off their UV emission spectrum.…
Gamma-ray bursts (GRBs) are flashes of high-energy radiation arising from energetic cosmic explosions. Bursts of long (>2 s) duration are produced by the core-collapse of massive stars, those of short (< 2 s) duration by the merger of two…
A gamma-ray burst (GRB) is a strong and fast gamma-ray emission from the explosion of stellar systems (massive stars or coalescing binary compact stellar remnants), happening at any possible redshift, and detected by space missions.…
Gamma-ray bursts (GRBs) are short and intense flashes at the cosmological distances, which are the most luminous explosions in the Universe. The high luminosities of GRBs make them detectable out to the edge of the visible universe. So,…
Growing observational evidence supports the proposition that gamma-ray bursts (GRBs) are powered by relativistic jets from massive helium stars whose cores have collapsed to black holes and an accretion disk (collapsars). We model the…
The extragalactic gamma-ray sky is dominated by two classes of sources: Gamma-Ray Bursts (GRBs) and radio loud active galactic nuclei whose jets are pointing at us (blazars). We believe that the radiation we receive from them originates…
A theory is proposed to explain with simplicity the basic observed properties of a Gamma Ray Burst (GRB). It employs a well-known result of Schwinger, that static electric fields in excess of a critical value are unstable to pair creation,…
Gamma-ray burst astronomy has undergone a revolution in the last three years, spurred by the discovery of fading long-wavelength counterparts. We now know that at least the long duration GRBs lie at cosmological distances with estimated…
Gamma-ray bursts (GRBs) are energetic explosions that for 0.01--100 s are the brightest gamma-ray sources in the sky. Observations of the early evolution of afterglows we expected to provide clues about the nature of the bursts, but their…
The duration of a gamma-ray burst (GRB) is a key indicator of its physics origin, with long bursts perhaps associated with the collapse of massive stars and short bursts with mergers of neutron stars.However, there is substantial overlap in…
Gamma-ray bursts (GRBs) divide into two classes: "long", which typically have initial durations of T90>2s, and "short", with durations of T90<2s (where T90 is the time to detect 90% of the observed fluence). Long bursts, which on average…
There is growing evidence that long and hard gamma-ray bursts (GRBs), discovered at redshifts between 0.4 and 3.4, are related to some type of supernova (SN) explosions. The GRB ejecta are ultra-relativistic, and possibly beamed. There is a…
Gamma-ray bursts (GRBs) are emitted by relativistic ejecta from powerful cosmic explosions. Their light curves suggest that the gamma-ray emission occurs at early stages of the ejecta expansion, well before it decelerates in the ambient…
We study the scenario where the gamma-ray bursts (GRBs) arise from core-collapse of very massive stars in star-forming regions in the starburst galaxies at high redshift. The bimodial structure of the gamma-ray bursts point to their…
The detection of flares with the Swift satellite triggered a lot of bservational and theoretical interest in these phenomena. As a consequence a large analysis effort started within the community to characterize the phenomenon and at the…
Over the past five years evidence has mounted that long-duration (> 2 s) gamma-ray bursts (GRBs)--the most brilliant of all astronomical explosions--signal the collapse of massive stars in our Universe. This evidence was originally based on…