Related papers: A Complexity-Brightness Correlation in Gamma Ray B…
The Robotic Optical Transient Search Experiment (ROTSE) seeks to measure simultaneous and early afterglow optical emission from gamma-ray bursts (GRBs). A search for optical counterparts to six GRBs with localization errors of 1 square…
The emission mechanism during the prompt phase in gamma-ray bursts (GRBs) can be investigated through correlations between spectral properties. Here, we revisit the correlation relating the instantaneous flux, $F$, and the photon index…
Gamma-ray bursts (GRB) are sudden, intense flashes of gamma-rays which, for a few blinding seconds, light up in an otherwise fairly dark gamma-ray sky. They are detected at the rate of about once a day, and while they are on, they outshine…
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,…
Starting from the Swift sample we define a complete sub-sample of 58 bright long Gamma Ray Bursts (GRB), 55 of them (95%) with a redshift determination, in order to characterize their properties. Our sample (BAT6) allows us to study the…
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…
Many gamma ray bursts (GRBs) have been observed with the Burst-Alert and X-Ray telescopes of the Swift satellite. The successive `pulses' of these GRBs end with a fast decline and a fast spectral softening, until they are overtaken by…
In an effort to understand the puzzle of classifying gamma-ray bursts (GRBs), we perform a systematic study of {\it Swift} GRBs and investigate several short GRB issues. Though short GRBs have a short ($\lesssim2$ s) prompt duration as…
The separation of the gamma-ray bursts (GRBs) into short/hard and long/soft subclasses, respectively, is well supported both theoretically and observationally. The long ones are coupled to supernovae type Ib/Ic - the short ones are…
We consider all bursts with known redshift and $\nu F_\nu$ peak energy, $E^{obs}_{peak}$. For a good fraction of them an estimate of the jet opening angle is available from the achromatic break of their afterglow light curve. This allows…
The positions of over 1000 gamma-ray bursts detected with the BATSE experiment on board of the Compton Gamma Ray Observatory are uniformly and randomly distributed in the sky, with no significant concentration to the galactic plane or to…
For gamma-ray bursts (GRBs) with durations greater than two seconds (so-called long GRBs), the intrinsic prompt gamma-ray emission appears, on average, to last longer for bursts at lower redshifts. We explore the nature of this…
We present several cases of optical observations during gamma-ray bursts (GRBs) which resulted in prompt limits but no detection of optical emission. These limits constrain the prompt optical flux densities and the optical brightness…
This paper reports statistically significant correlations between various burst parameters, observed in a sample of 156 GRBs belonging to BATSE 4B catalog with T90 less than 2 s. The number of subpulses in a burst is strongly correlated not…
We study the power density spectrum (PDS) of artificial light curves of observed gamma-ray bursts (GRBs). We investigate statistical properties of GRB light curves by comparing the reported characteristics in the PDSs of the observed GRBs…
Gamma-Ray Bursts (GRBs) are extra-galactic and extremely energetic transient emissions of gamma rays, which are thought to be associated with the death of massive stars or the merger of compact objects in binary systems. Their huge…
The observation by the BATSE instrument on the Compton Gamma Ray Observatory that gamma-ray bursts (GRBs) are distributed isotropically around the Earth but nonuniformly in distance has led to the widespread conclusion that GRBs are most…
We present a carefully selected sub-sample of Swift Long Gamma-ray Bursts (GRBs), that is complete in redshift. The sample is constructed by considering only bursts with favorable observing conditions for ground-based follow-up searches,…
Compact object mergers, or their collisions in dense stellar environments, involve different time scales. Each of these has its own tempo and dictates a characteristic set of consequences which may, or may not, be observable in what we see…
A quantitative theory of spectral lags for $\gamma$-ray bursts (GRBs) is given. The underlying hypothesis is that GRB subpulses are photons that are scattered into our line of sight by local concentrations of baryons that are accelerated by…