Related papers: Swift X-ray Afterglows and the Missing Jet Break P…

We present science highlights and performance from the Swift X-ray Telescope (XRT), which was launched on November 20, 2004. The XRT covers the 0.2-10 keV band, and spends most of its time observing gamma-ray burst (GRB)afterglows, though…

The optical and X-ray light-curves of long Gamma Ray Bursts (GRBs) often show a complex evolution and in most cases do not track each other. This behaviour can not be easily explained by the simplest standard afterglow models. A possible…

We show that all X-ray decay curves of GRBs measured by Swift can be fitted using one or two components both of which have exactly the same functional form comprised of an early falling exponential phase followed by a power law decay. The…

We report the results of Swift X-Ray Telescope (XRT) observations of GRB 050318. This event triggered the Burst Alert Telescope (BAT) aboard Swift and was followed-up with XRT and UVOT for 11 consecutive orbits starting from 54 minutes…

The Swift era has posed a challenge to the standard blast-wave model of Gamma Ray Burst (GRB) afterglows. The key observational features expected within the model are rarely observed, such as the achromatic steepening (`jet-break') of the…

The X-ray light-curves of the GRB afterglows monitored by Swift display one to four phases of power-law decay. In chronological order they are: the burst tail, the "hump", the standard decay, and the post jet-break decay. The large-angle…

Swift discovered XRF 050416A with the BAT and began observing it with its narrow field instruments only 64.5 s after the burst onset. Its very soft spectrum classifies this event as an X-ray flash. The afterglow X-ray emission was monitored…

I discuss some theoretical expectations for the synchrotron emission from a relativistic blast-wave interacting with the ambient medium, as a model for GRB afterglows, and compare them with observations. An afterglow flux evolving as a…

The Swift mission has discovered an intriguing feature of Gamma-Ray Burst (GRBs) afterglows, a phase of shallow decline of the flux in the X-ray and optical lightcurves. This behaviour is typically attributed to energy injection into the…

The availability of multi-wavelength high-quality data of gamma-ray burst afterglows in the Swift era, contrary to the expectations, did not allow us to fully confirm yet one of the most fundamental features of the standard afterglow…

Using the 8.4m Large Binocular Telescope, we observed six GRB afterglows from 2.8 hours to 30.8 days after the burst triggers to systematically probe the late time behaviors of afterglows including jet breaks, flares, and supernova bumps.…

We present the observations of the afterglow of gamma-ray burst GRB 090102. Optical data taken by the TAROT, REM, GROND, together with publicly available data from Palomar, IAC and NOT telescopes, and X-ray data taken by the XRT instrument…

Swift discovered the high redshift GRB 050319 with the Burst Alert Telescope and began observing with its narrow field instruments only 225 s after the burst onset. The afterglow X-ray emission was monitored by the XRT up to 28 days after…

The X-ray afterglows observed by Swift exhibit rich light-curves, with four phases of different decay rate. The temporal and spectral properties for a set of 47 bursts are used to identify the mechanisms which can explain these four phases.…

X-ray flashes (XRFs) and X-ray rich gamma-ray bursts (XRGRBs) share many observational characteristics with long duration GRBs, but the reason for which their prompt emission peaks at lower photon energies, $E_p$, is still under debate.…

Swift-detected GRB 080307 showed an unusual smooth rise in its X-ray light-curve around 100 seconds after the burst, at the start of which the emission briefly softened. This `hump' has a longer duration than is normal for a flare at early…

We report on 5 Chandra observations of the X-ray afterglow of the Gamma-Ray Burst GRB 060729 performed between 2007 March and 2008 May. In all five observations the afterglow is clearly detected. The last Chandra pointing was performed on…

Based on the early-year observations from Neil Gehrels \emph{Swift} Observatory, \cite{liang07} performed a systematic analysis for the shallow decay component of gamma-ray bursts (GRBs) X-ray afterglow, in order to explore its physical…

Sharp breaks have been observed in the afterglow light curves of several GRBs; this is generally explained by the jet model. However, there are still some uncertainties concerning this interpretation due to the unclear hydrodynamics of jet…

We present an analysis of the unusual optical light curve of the gamma-ray burst GRB 081029, a long-soft burst with a redshift of z = 3.8479. We combine X-ray and optical observations from the Swift X-Ray Telescope and the Swift…