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Related papers: Flares in Gamma Ray Bursts (II)

200 papers

We present the results of observations of the soft gamma-ray early afterglows with the energy above 100keV from two bright Gamma-ray bursts detected by the PHEBUS instrument of the GRANAT orbital observatory. We show that the light curves…

Astrophysics · Physics 2008-11-26 A. Tkachenko , O. Terekhov , R. Sunyaev , R. Burenin , C. Barat , J. -P. Dezalay , G. Vedrenne

Extended emission is a mystery in short gamma-ray bursts (SGRBs). By making time resolved spectral analyses of brightest nine events observed by ${\it Swift}$ XRT, we obviously classify the early X-ray emission of SGRBs into two types. One…

High Energy Astrophysical Phenomena · Physics 2015-11-30 Yasuaki Kagawa , Daisuke Yonetoku , Tatsuya Sawano , Asuka Toyanago , Takashi Nakamura , Keitaro Takahashi , Kazumi Kashiyama , Kunihito Ioka

We study the duration and variability of late time X-ray flares following gamma-ray bursts (GRBs) observed by the narrow field X-ray telescope (XRT) aboard the {\it Swift} spacecraft. These flares are thought to be indicative of late time…

Astrophysics · Physics 2009-11-13 Daniel Kocevski , Nathaniel Butler , Joshua S. Bloom

The origin of prompt emission from gamma ray bursts remains to be an open question. Correlated prompt optical and gamma-ray emission observed in a handful of GRBs strongly suggests a common emission region, but failure to adequately fit the…

High Energy Astrophysical Phenomena · Physics 2016-12-21 S. Guiriec , C. Kouveliotou , D. H. Hartmann , J. Granot , K. Asano , P. Meszaros , R. Gill , N. Gehrels , J. McEnery

We statistically study gamma-ray burst (GRB) optical flares from the Swift/UVOT catalog. We compile 119 optical flares, including 77 flares with redshift measurements. Some tight correlations among the time scales of optical flares are…

High Energy Astrophysical Phenomena · Physics 2017-08-02 Shuang-Xi Yi , Hai Yu , F. Y. Wang , Z. G. Dai

We present a numerical simulation of a gamma-ray burst jet from a long-lasting engine in the core of a 16 solar mass Wolf-Rayet star. The engine is kept active for 6000 s with a luminosity that decays in time as a power-law with index -5/3.…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Davide Lazzati , Chris H. Blackwell , Bran J. Morsony , Mitch C. Begelman

We present results from extensive broadband follow-up of GRB 210204A over the period of thirty days. We detect optical flares in the afterglow at 7.6 x 10^5 s and 1.1 x 10^6 s after the burst: the most delayed flaring ever detected in a GRB…

According to current models, gamma-ray bursts (GRBs) are produced when the energy carried by a relativistic outflow is dissipated and converted into radiation. The efficiency of this process, $\epsilon_\gamma$, is one of the critical…

Astrophysics · Physics 2009-11-11 Jonathan Granot , Arieh Konigl , Tsvi Piran

The light curve, energy characteristics, and localization of a short/hard GRB 051103 burst are considered. Evidence in favor of identifying this event with a giant flare from a soft gamma repeater in the nearby M81 group of interacting…

Long gamma-ray bursts (GRBs), which signify the end-life collapsing of very massive stars, are produced by extremely relativistic jets colliding into circumstellar medium. Huge energy is released both in the first few seconds, namely the…

3C 454.3 is frequently observed in flaring state. The long term light curve of this source has been analysed with 9 year (August 2008 - July 2017) data from Fermi LAT detector. We have identified five flares and one quiescent state. The…

High Energy Astrophysical Phenomena · Physics 2020-05-06 Avik Kumar Das , Raj Prince , Nayantara Gupta

The recent years witnessed a dramatic improvement in our knowledge of the phenomenology and physics of Gamma Ray Bursts (GRBs). However, our "pillars of knowledge" remain a few, while many aspects remain obscure and not understood. There is…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Gabriele Ghisellini

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…

High Energy Astrophysical Phenomena · Physics 2009-08-05 M. Nardini , G. Ghisellini , G. Ghirlanda , A. Celotti

We report on the temporal and spectral characteristics of the early X-ray emission from the GRB 050822 as observed by Swift. This burst is likely to be an XRF showing major X-ray flares in its XRT light-curve. The quality of the data allows…

We present a multi-wavelength analysis of gamma-ray burst GRB 090727, for which optical emission was detected during the prompt gamma-ray emission by the 2-m autonomous robotic Liverpool Telescope and subsequently monitored for a further…

High Energy Astrophysical Phenomena · Physics 2015-06-16 D. Kopac , S. Kobayashi , A. Gomboc , J. Japelj , C. G. Mundell , C. Guidorzi , A. Melandri , D. Bersier , Z. Cano , R. J. Smith , I. A. Steele , F. J. Virgili

Gamma-ray bursts (GRBs) are short and intense emission of soft gamma-rays, which have fascinated astronomers and astrophysicists since their unexpected discovery in 1960s. The X-ray/optical/radio afterglow observations confirm the…

Astrophysics · Physics 2009-05-07 Yi-Zhong Fan , Tsvi Piran

While Gamma Ray Bursts (GRBs) have the potential to shed light on the astrophysics of jets, compact objects, and cosmology, a major set back in their use as probes of these phenomena stems from our incomplete knowledge surrounding their…

High Energy Astrophysical Phenomena · Physics 2024-08-12 Tyler Parsotan , Davide Lazzati

We present a new algorithm for the detection of flares in gamma-ray burst (GRB) light curves and use this algorithm to detect flares in the UV/optical. The algorithm makes use of the Bayesian Information Criterion (BIC) to analyze the…

High Energy Astrophysical Phenomena · Physics 2013-08-22 C. A. Swenson , P. W. A. Roming , M. De Pasquale , S. R. Oates

GRB 050904 at redshift z=6.29, discovered and observed by Swift and with spectroscopic redshift from the Subaru telescope, is the first gamma-ray burst to be identified from beyond the epoch of reionization. Since the progenitors of long…

Astrophysics · Physics 2010-11-11 L. J. Gou , D. B. Fox , P. Meszaros

Previous research on Lorentz invariance violation in photons from gamma-ray bursts (GRBs) suggested a scenario where multi-GeV photons could be emitted before lower-energy photons at the GRB source frame. This implies the existence of a new…

High Energy Astrophysical Phenomena · Physics 2024-10-17 Qing Liu , Hanlin Song , Bo-Qiang Ma