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Related papers: Did Swift measure GRB prompt emission radii?

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The early X-ray afterglow for a significant number of gamma-ray bursts detected by the Swift satellite is observed to have a phase of very slow flux decline with time ($F_\nu \propto t^{-\alpha}$ with $0.2 \lesssim \alpha \lesssim 0.8$) for…

Astrophysics · Physics 2009-11-13 Jonathan Granot , Pawan Kumar

We summarise the X-ray temporal and spectral variability properties of GRBs as observed using the Swift satellite. Despite much individual complexity, the flux and spectral variability can be reasonably well described by a combination of…

Astrophysics · Physics 2009-11-13 Paul O'Brien , Richard Willingale

(Abridged) The Swift X-Ray Telescope (XRT) reveals some interesting features of early X-ray afterglows, including a distinct rapidly decaying component preceding the conventional afterglow component in many sources, a shallow decay…

The X-ray light curves of many gamma-ray bursts (GRBs) observed by the Swift X-Ray Telescope (XRT) have a very steep-decay component (tail) following the prompt gamma-rays in the early phase and have some erratic flares occurring at a time…

The instantaneous emission from a relativistic surface endowed with a Lorentz factor $\Gamma$ that decreases away from the outflow symmetry axis can naturally explain the three phases observed by Swift/XRT in GRBs and their afterglows (GRB…

High Energy Astrophysical Phenomena · Physics 2025-05-13 A. Panaitescu

The X-ray light curves of hundreds of bursts are now available, thanks to the X-ray Telescope on board the Swift satellite, on time scales from ~1 minute up to weeks and in some cases months from the burst explosion. These data allow us to…

Astrophysics · Physics 2007-05-23 G. Tagliaferri

X-ray flares were discovered in the afterglow phase of gamma-ray bursts (GRBs) by the {\em Swift} satellite a decade ago and known as a canonical component in GRB X-ray afterglows. In this paper, we constrain the Lorentz factors of GRB…

High Energy Astrophysical Phenomena · Physics 2015-07-15 Shuang-Xi Yi , Xue-Feng Wu , Fa-Yin Wang , Zi-Gao Dai

Observations of gamma ray bursts (GRBs) with Swift produced the initially surprising result that many bursts have large X-ray flares superimposed on the underlying afterglow. These flares were sometimes intense, rapid, and late relative to…

We present the time-resolved optical emission of GRB 060111B during its prompt phase, measured with the TAROT robotic observatory. This is the first time that the optical emission from a gamma-ray burst has been continuously monitored with…

Previously detected in only a few gamma-ray bursts (GRBs), X-ray flares are now observed in ~50% of Swift GRBs, though their origins remain unclear. Most flares are seen early on in the afterglow decay, while some bursts exhibit flares at…

We report on a comprehensive set of observations of Gamma Ray Burst 050716, detected by the Swift satellite and subsequently followed-up rapidly in X-ray, optical and near infra-red wavebands. The prompt emission is typical of long-duration…

The Swift XRT has been observing GRB afterglows since December 23, 2004. Three-quarters of these observations begin within 300 s of the burst onset, providing an unprecendented look at the behavior of X-ray emission from GRB afterglows in…

We selected a sample of 33 Gamma Ray Bursts (GRBs) detected by Swift, with known redshift and optical extinction at the host frame. For these, we constructed the de-absorbed and K-corrected X-ray and optical rest frame light curves. These…

Astrophysics · Physics 2009-11-13 G. Ghisellini , M. Nardini , G. Ghirlanda , A. Celotti

The transition from prompt to the afterglow emission is one of the most exciting and least understood phases in gamma-ray bursts (GRBs). Correlations among optical, X-ray and gamma-ray emission in GRBs have been explored, to attempt to…

We investigated the main prompt and afterglow emission parameters of gamma-ray bursts detected by the Burst Alert Telescope (BAT) and X-Ray Telescope installed on the Swift satellite. Our aim was to look for differences or connections…

High Energy Astrophysical Phenomena · Physics 2013-09-05 J. Kóbori , Z. Bagoly , L. G. Balázs , I. Horváth

Based on light curves from the Swift Burst Analyser, we investigate whether a `dip' feature commonly seen in the early-time hardness ratios of Swift-XRT data could arise from the juxtaposition of the decaying prompt emission and rising…

High Energy Astrophysical Phenomena · Physics 2015-05-27 P. A. Evans , J. P. Osborne , R. Willingale , P. T. O'Brien

The detection of flares with the Swift satellite triggered a lot of bservational and theoretical interest in these phenomena. As a consequence a large analysis effort started within the community to characterize the phenomenon and at the…

Since the advent of the Swift satellite it has been possible to obtain precise localisations of GRB positions of sub-arcsec accuracy within seconds, facilitating ground-based robotic telescopes to automatically slew to the target within…

We present the time-resolved optical emission of gamma-ray bursts GRB 060904B and GRB 070420 during their prompt and early afterglow phases. We used time resolved photometry from optical data taken by the TAROT telescope and time resolved…

Astrophysics · Physics 2009-11-13 A. Klotz , B. Gendre , G. Stratta , A. Galli , A. Corsi , B. Preger , S. Cutini , A. Pelangeon , J. L. Atteia , M. Boer , L. Piro