Related papers: GRB 090227B: the missing link between the genuine …
In the internal shock scenario for GRBs we expect some fraction of the energy of the burst to be carried by slow moving shells that were ejected at late times. These slow shells collide with faster moving outer shells when the outer shells…
We present detailed, multi-wavelength analysis of GRB 210704A: a Fermi Gamma-ray Burst Monitor discovered and Fermi Large Area Telescope (LAT) detected gamma-ray burst (GRB). The burst is dominated by a short ($\approx 2$ s) pulse followed…
The X and gamma-ray observations of the source GRB 031203 by INTEGRAL are interpreted within our theoretical model. In addition to a complete space-time parametrization of the GRB, we specifically assume that the afterglow emission…
We present here our results of the temporal and spectral analysis of a sample of 52 bright and hard gamma-ray bursts (GRBs) observed with the Fermi Gamma-ray Burst Monitor (GBM) during its first year of operation (July 2008-July 2009). Our…
Our knowledge of the intrinsic properties of short duration Gamma-Ray Bursts has relied, so far, only upon a few cases for which the estimate of the distance and an extended, multiwavelength monitoring of the afterglow have been obtained.…
The optical-infrared afterglow of the LAT-detected long duration burst, GRB 090902B, has been observed by several instruments. The earliest detection by ROTSE-IIIa occurred 80 minutes after detection by the GBM instrument onboard the Fermi…
The long-lasting tension between the observed spectra of gamma ray bursts (GRBs) and the predicted synchrotron emission spectrum might be solved if electrons do not completely cool. Evidence for incomplete cooling was recently found in…
Within the "fireshell" model for the Gamma-Ray Bursts (GRBs) 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…
A long and intense gamma-ray burst (GRB) was detected by INTEGRAL on July 11 2012 with a duration of ~115s and fluence of 2.8x10^-4 erg cm^-2 in the 20 keV-8 MeV energy range. GRB 120711A was at z~1.405 and produced soft gamma-ray emission…
GRB spectra appear non-thermal, but recent observations of a few bursts with Fermi GBM have confirmed previous indications from BATSE of the presence of an underlying thermal component. Photospheric emission is indeed expected when the…
We present a comparative study of the observed properties of the optical and X-ray afterglows of short- and long-duration gamma-ray bursts (GRBs). Using a large sample of 37 short and 421 long GRBs, we find a strong correlation between the…
We report a multi-wavelength analysis of the prompt emission and early afterglow of GRB051111 and discuss its properties in the context of current fireball models. The detection of GRB051111 by the Burst Alert Telescope on-board Swift…
Using high-quality, broad-band afterglow data for GRB 091127, we investigate the validity of the synchrotron fireball model for gamma-ray bursts, and infer physical parameters of the ultra-relativistic outflow. We used multi-wavelength…
We plan to fit the complete gamma- and X-ray light curves of the long duration GRB060218, including the prompt emission, in order to clarify the nature of the progenitors and the astrophysical scenario of the class of GRBs associated to SNe…
GRB 130925A is an ultra-long GRB, and it shows clear evidences for a thermal emission in the soft X-ray data of \emph{Swift}/XRT ($\sim0.5$\,keV), lasting till the X-ray afterglow phase. Due to the long duration of the GRB, the burst could…
Using the Swift data of GRB 050315, we progress on the uniqueness of our theoretically predicted Gamma-Ray Burst (GRB) structure as composed by a proper-GRB (P-GRB), emitted at the transparency of an electron-positron plasma with suitable…
We perform a statistical analysis of the temporal and spectral properties of the latest Fermi gamma-ray bursts (GRBs) to revisit the classification of GRBs. We find that the bimodalities of duration and the energy ratio…
We present the results of a comprehensive study of the luminosity function, energetics, prompt gamma-ray correlations, and classification methodology of short-hard and long-soft GRBs (SGRBs and LGRBs), based on observational data in the…
We have conducted a thorough and blind search for emission lines in >70 Swift X-ray afterglows of total exposure ~10^7s. We find that most afterglows are consistent with pure power-laws plus extinction. Significant outliers to the…
A few long gamma-ray bursts such as GRB 050421 show no afterglow emission beyond the usual initial steep decay phase. It has been suggested that these events correspond to "naked" bursts that occur in a very low density environment. We…