Related papers: GRB060218: A Relativistic Supernova Shock Breakout
Excess reddened optical emission has been measured in the power-law decay afterglow light curves of several GRBs some tens of days after the GRB events. This emission is claimed to be a signature of a supernova (SN) taking place at the same…
Long gamma-ray bursts (GRBs) are commonly accepted to originate in the explosion of particularly massive stars, which gives rise to a highly relativistic jet. Internal inhomogeneities in the expanding flow give rise to internal shock waves…
Four years after the launch the Swift satellite the nature of the Gamma Ray Bursts (GRBs) broadband afterglow behaviour is still an open issue ad the standard external shock fireball models cannot easily explain the puzzling combined…
Models where relativistic jets from merger or accretion induced collapse in compact binary systems produce cosmological gamma ray bursts (GRBs) also predict that GRBs are accompanied by delayed emission of high energy photons, TeV…
We present observations of GRB 060124, the first event for which both the prompt and the afterglow emission could be observed simultaneously and in their entirety by the three Swift instruments and by Konus-Wind. Thanks to these exceptional…
Understanding the origin and diversity of emission processes responsible for Gamma-ray Bursts (GRBs) remains a pressing challenge. While prompt and contemporaneous panchromatic observations have the potential to test predictions of the…
Observations of the afterglows of gamma-ray bursts (GRBs) have revealed that they lie at cosmological distances, and so correspond to the release of an enormous amount of energy. The nature of the central engine that powers these events and…
Long gamma-ray bursts (GRBs) are characterized by a brief gamma-ray flash followed by a longer-lasting multiwavelength afterglow. The basic mechanism is largely understood, and the early afterglow evolution often shows complex features that…
We report on observations of GRB 080503, a short gamma-ray burst with very bright extended emission (about 30 times the gamma-ray fluence of the initial spike) in conjunction with a thorough comparison to other short Swift events. In spite…
Recent observations suggest that gamma ray bursts (GRBs) and their afterglows are produced by highly relativistic jets emitted in core collapse supernova explosions (SNe). The result of the event, probably, is not just a compact object plus…
The finding of a Type Ic supernova connected with GRB 030329 showed a massive star origin for this burst, supporting evidence for this association in previous bursts with lightcurve bumps at the appropriate time for a supernova. Here, we…
Context: Multiwavelength observations of gamma-ray burst prompt and afterglow emission are a key tool to disentangle the various possible emission processes and scenarios proposed to interpret the complex gamma-ray burst phenomenology.…
The most common progenitors of gamma-ray bursts (GRBs) are massive stars with strong stellar winds. We show that the GRB blast wave in the wind should emit a bright GeV flash. It is produced by inverse Compton cooling of the thermal plasma…
Early optical observations of gamma-ray bursts can significantly contribute to the study of the central engine and physical processes therein. However, of the thousands observed so far, still only a few have data at optical wavelengths in…
We present a detailed analysis of Swift multi-wavelength observations of GRB 070110 and its remarkable afterglow. The early X-ray light curve, interpreted as the tail of the prompt emission, displays a spectral evolution already seen in…
We discuss observations of the prompt X and gamma-ray emission and X-ray afterglow from GRB981226. This event has the weakest gamma-ray peak flux detected with the Gamma-Ray Burst Monitor. It shows an isolated X-ray precursor and the…
We report the detection of a faint optical flash by the 2-m Faulkes Telescope North simultaneously with the second of two prompt gamma-ray pulses in INTEGRAL gamma-ray burst (GRB) 080603A, beginning at t_rest = 37 s after the onset of the…
We investigate by two-dimensional axisymmetric relativistic hydrodynamical simulations (1) jet propagations through an envelope of a rapidly rotating and collapsing massive star, which is supposed to be a progenitor of long duration gamma…
When a relativistic jet is launched following the core-collapse of a star, its interaction with the stellar envelope leads to the formation of a hot cocoon, which produces various viewing-angle-dependent observational phenomena following…
Gamma-ray Bursts (GRBs) generate powerful relativistic jets that inject a large amount of energy into their surrounding environment, producing blast waves that accelerate particles to high energies. The GRB afterglow radiation provides a…