Related papers: GRB060614: a "fake" short GRB from a merging binar…

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…

Context: GRB110709B is the first source for which Swift BAT triggered twice, with a time separation of ~10 min. The first emission (Ep. 1) goes from 40s before the 1{\deg} trigger up to 60s after it. The second (Ep. 2) goes from 35s before…

Following the faint gamma-ray burst, GRB 170817A, coincident with a gravitational wave-detected binary neutron star merger at $d\sim40$ Mpc, we consider the constraints on a local population of faint short duration GRBs (defined here…

Gamma-ray bursts (GRBs) display a bimodal duration distribution, with a separation between the short- and long-duration bursts at about 2 sec. The progenitors of long GRBs have been identified as massive stars based on their association…

The luminosity and the spectral distribution of the afterglow of GRB 031203 have been presented within our theoretical framework, which envisages the GRB structure as composed by a proper-GRB, emitted at the transparency of an…

GRB061007 is the brightest gamma-ray burst (GRB) to be detected by Swift and is accompanied by an exceptionally luminous afterglow that had a V-band magnitude <11.1 at 80s after the prompt emission. From the start of the Swift observations…

Gamma-ray bursts (GRBs) are among the brightest and most energetic events in the universe. The duration and hardness distribution of GRBs has two clusters, now understood to reflect (at least) two different progenitors. Short-hard GRBs…

We have gathered optical photometry data from the literature on a large sample of Swift-era gamma-ray burst (GRB) afterglows including GRBs up to September 2009, for a total of 76 GRBs, and present an additional three pre-Swift GRBs not…

GRB 030329 is unique in many aspects. It has a very low redshift for a GRB, $z=0.1685$, and is therefore very bright and easy to monitor, making it the most well studied afterglow to date. It shows a supernova bump in the light curve, with…

Most long gamma-ray bursts (GRBs) exhibit afterglows broadly consistent with external forward-shock emission, typically described by smooth broken power-law decays in the multiband light curve. However, a minority of well-sampled GRBs…

The fraction of long duration gamma ray bursts (GRBs) without an associated bright supernovae (SNe) at small redshifts $(z<0.15)$ is comparable to that of GRBs associated with SNe. We show, that their X-ray afterglow and the X-ray afterglow…

Within the "fireshell" model we define a "canonical GRB" light curve with two sharply different components: the Proper-GRB (P-GRB), emitted when the optically thick fireshell of electron-positron plasma originating the phenomenon reaches…

The highly variable and energetic pulsed emission of a long gamma-ray burst (GRB) is thought to originate from local, rapid dissipation of kinetic or magnetic energy within an ultra-relativistic jet launched by a newborn compact object,…

Context. GRB050721 was detected by Swift and promptly followed-up, in the X-ray by Swift itself and, in the optical band, by the VLT operated, for the first time, in rapid response mode. A multiwavelength monitoring campaign was performed…

We present the results of an optical and near-infrared (NIR) monitoring campaign of the counterpart of Gamma-Ray Burst (GRB) 000911, located at redshift z=1.06, from 5 days to more than 13 months after explosion. Our extensive dataset is a…

We review recent progress in our understanding of the nature of gamma ray bursts (GRBs) and in particular, of the relationship between short GRBs and long GRBs. The first example of a short GRB is described. The coincidental occurrence of a…

We present the results of a comprehensive study of the gamma-ray burst 080928 and of its afterglow. GRB 080928 was a long burst detected by Swift/BAT and Fermi/GBM. It is one of the exceptional cases where optical emission had already been…

Despite the pre-Swift expectation that bright optical flashes from reverse shocks would be prevalent in early-time afterglow emission, rapid response observations show this not to be the case. Although very bright at early times, some GRBs…

We present a multiwavelength study of GRB 151027A. This is the 999th GRB detected by the Swift satellite and it has a densely sampled emission in the X-ray and optical band and has been observed and detected in the radio up to 140 days…

Over the six years since the discovery of the gamma-ray burst GRB 980425, associated with the nearby (distance, ~40 Mpc) supernova 1998bw, astronomers have fiercely debated the nature of this event. Relative to bursts located at…