Related papers: A Universal Central Engine Hypothesis for Short an…
Long-duration, spectrally-soft Gamma-Ray Bursts (GRBs) are associated with Type Ic Core Collapse (CC) Supernovae (SNe), and thus arise from the death of massive stars. In the collapsar model, the jet launched by the central engine must bore…
GRBs are thought to arise in relativistic blast-wave shocks at distances of 10 to 1000 AU from the point where the explosive energy is initially released. To account for the observed duration and variability of the gamma-ray emission in…
After decades of observations the physical mechanisms that generate short gamma-ray bursts (SGRBs) still remain unclear. Observational evidence provides support to the idea that SGRBs originate from the merger of compact binaries,…
We build a comprehensive sample to statistically describe the properties of X-ray flashes (XRFs) and X-ray riches (XRRs) from the latest third Swift Burst Alert Telescope (BAT3) catalog of Gamma-ray bursts (GRBs). We obtain 81 XRFs, 540…
Swift-XRT observations of the X-ray emission from gamma ray bursts (GRBs) and during the GRB afterglow have led to many new results during the past two years. One of these exciting results is that approximately 1/3-1/2 of GRBs contain…
Short Gamma-Ray Bursts (GRBs) are explosions of cosmic origin believed to be associated with the merger of two compact objects, either two neutron stars, or a neutron star and a black hole. The presence of at least one neutron star has long…
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…
Magnetars are modelled as sources that derive their output from magnetic energy that substantially exceeds their rotational energy. An implication of the recent polarization measurement of GRB 021206 is that the emission mechanism may be…
It is shown that short and long gamma ray bursts (GRBs) are of the same origin and, furthermore, correlated with their duration.
X-ray flashes (XRFs) are a class of high-energy transients whose nature is still open to question. Similar in many aspects to common gamma-ray bursts (GRBs), their strong X-ray emission is accompanied by very low or absent emission in the…
Gamma-ray bursts (GRB) are short and intense bursts of $\sim$100 keV$-$1MeV photons, usually followed by long-lasting decaying afterglow emission in a wide range of electromagnetic wavelengths from radio to X-ray and, sometimes, even to GeV…
Early-time X-ray observations of GRBs with the Swift satellite have revealed a more complicated phenomenology than was known before. In particular, the presence of flaring activity on a wide range of time scales probably requires late-time…
Evidence for the central engine of gamma-ray bursts (GRBs) has been collected in the Neil Gehrels \emph{Swift} data. For instance, some GRBs show an internal X-ray plateau followed by very steep decay, which is difficult to be interpreted…
Short-hard and long-soft gamma-ray bursts (GRBs) are two distinct phenomena, but their prompt and afterglow emission show many similarities. This suggests that two different progenitor systems lead to similar physical processes and that the…
The central engine of Gamma Ray Bursts is hidden from direct probing with photons mainly due to the high densities involved. Inferences on their properties are thus made from their cosmological setting, energetics, low-energy counterparts…
GRB 120422A is a low-luminosity Gamma-ray burst (GRB) associated with a bright supernova, which distinguishes itself by its relatively short T90 ~ 5 s and an energetic X-ray tail. We analyze the Swift BAT and XRT data and discuss the…
We analyze a sample of\textit{ Swift} gamma-ray bursts (GRBs) with extended emissions in $\gamma$-rays and/or X-ray plateaus that may be driven by magnetars. Multi-wavelength data and multi-standards have been adopted to investigate the…
Short gamma-ray bursts (SGRBs) are among the most luminous explosions in the Universe and their origin still remains uncertain. Observational evidence favors the association with binary neutron star or neutron star-black hole (NS-BH) binary…
The energy release in gamma-ray bursts is one of the most interesting clues on the nature of their "inner engines". We show here that the total energy release in GRBs varies by less than one order of magnitude from one burst to another…
In this paper we give a brief review of our recent studies on the long and short gamma-ray bursts (GRBs) detected Swift, in an effort to understand the puzzle of classifying GRBs. We consider that it is still an appealing conjecture that…