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Related papers: The Spectral Sharpness Angle of Gamma-ray Bursts

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Gamma-ray bursts are the most energetic electromagnetic sources in the Universe. Their prompt gamma-ray radiation corresponds to an energy release of 1E42-1E47J. Fifty years after their discovery and several dedicated space-based…

High Energy Astrophysical Phenomena · Physics 2019-10-22 J. Michael Burgess , Damien Bégué , Ana Bacelj , Dimitrios Giannios , Francesco Berlato , Jochen Greiner

Gamma-ray bursts (GRBs) are highly variable and exhibit strong spectral evolution. In particular, the emission properties vary from pulse to pulse in multipulse bursts. Here we present a time-resolved Bayesian spectral analysis of a…

High Energy Astrophysical Phenomena · Physics 2021-12-20 Liang Li , Felix Ryde , Asaf Pe'er , Hoi-Fung Yu , Zeynep Acuner

There is no complete description of the emission physics during the prompt phase in gamma-ray bursts. Spectral analyses, however, indicate that many spectra are narrower than what is expected for non-thermal emission models. Here, we…

High Energy Astrophysical Phenomena · Physics 2020-05-06 Zeynep Acuner , Felix Ryde , Asaf Pe'er , Daniel Mortlock , Björn Ahlgren

It has been suggested that the prompt emission in gamma-ray bursts consists of several components giving rise to the observed spectral shape. Here we examine a sample of the 8 brightest, single pulsed {\it Fermi} bursts whose spectra are…

High Energy Astrophysical Phenomena · Physics 2016-01-27 S. Iyyani , F. Ryde , J. M. Burgess , A. Pe'er , D. B\' egué

Sorted by the photon fluences of short Gamma-ray Bursts (SGRBs) detected by the Fermi- Gamma Ray Burst Monitor (GBM), nine brightest bursts are selected to perform a comprehensive analysis. All GRB lightcurves are fitted well by 1 to 3…

High Energy Astrophysical Phenomena · Physics 2022-03-10 Peng-Wei Zhao , Qing-Wen Tang

The prompt emission of gamma-ray bursts remains mysterious since the mechanism is difficult to understand even though there are much more observations with the development of detection technology. But most of the gamma-ray bursts spectra…

High Energy Astrophysical Phenomena · Physics 2020-02-26 Ming-Ya Duan , Xiang-Gao Wang

The radiative process responsible for gamma-Ray Burst (GRB) prompt emission has not been identified yet. If dominated by fast-cooling synchrotron radiation, the part of the spectrum immediately below the $\nu F_\nu$ peak energy should…

High Energy Astrophysical Phenomena · Physics 2017-09-20 Gor Oganesyan , Lara Nava , Giancarlo Ghirlanda , Annalisa Celotti

We aim to obtain high-quality time-resolved spectral fits of gamma-ray bursts (GRBs) observed by the Gamma-ray Burst Monitor (GBM) on board the Fermi Gamma-ray Space Telescope. We perform time-resolved spectral analysis with high temporal…

After seven years of science operation, the Fermi mission has brought great advances in the study of Gamma-ray Bursts (GRBs). Over 1600 GRBs have been detected by the Gamma-ray Burst Monitor, and more than 100 of these are also detected by…

High Energy Astrophysical Phenomena · Physics 2015-07-19 Elisabetta Bissaldi , Francesco Longo , Nicola Omodei , Giacomo Vianello , Andreas von Kienlin

In this paper, we explore time resolved Gamma-Ray Burst (GRB) spectra in the context of the synchrotron emission model presented in Lloyd and Petrosian (2000; LP00). First, we show that our model - which involves three distinct emission…

Astrophysics · Physics 2009-11-07 Nicole M. Lloyd-Ronning , Vahe' Petrosian

We investigate synchrotron emission models as the source of gamma-ray burst spectra. We show that including the possibility for synchrotron self-absorption, a ``smooth cutoff'' to the electron energy distribution, and an anisotropic…

Astrophysics · Physics 2018-11-06 Nicole M. Lloyd-Ronning , Vahe' Petrosian

We examine 288 GRBs detected by the Fermi Gamma-ray Space Telescope's Gamma-ray Burst Monitor (GBM) that fell within the field-of-view of Fermi's Large Area Telescope (LAT) during the first 2.5 years of observations, which showed no…

High Energy Astrophysical Phenomena · Physics 2015-06-03 LAT Collaboration , GBM Collaboration

The prompt phase X- and $\gamma$-ray light curves of gamma-ray bursts (GRBs) exhibit erratic and complex behaviour, often with multiple pulses. The temporal shape of individual pulses is often modelled as 'fast rise exponential decay'…

High Energy Astrophysical Phenomena · Physics 2025-07-14 A Gowri , A. Pe'er , F. Ryde , H. Dereli-Bégué

The observations of the prompt emission of gamma ray bursts (GRB) by GLAST Burst Monitor (GBM), on board Fermi Gamma-ray Space Telescope, suggest the presence of a significant thermal spectral component, whose origin is not well understood.…

High Energy Astrophysical Phenomena · Physics 2017-03-29 Priya Bharali , Sunder Sahayanathan , Ranjeev Misra , Kalyanee Boruah

We present the time integrated and time resolved spectral analysis of a sample of bright bursts selected with F_{peak}>20 phot cm^{-2} sec^{-1} from the BATSE archive. We fitted four different spectral models to the pulse time integrated…

Astrophysics · Physics 2009-11-07 G. Ghirlanda , A. Celotti , G. Ghisellini

The Fermi Gamma-Ray Space Telescope has more than doubled the number of Gamma-Ray Bursts (GRBs) detected above 100 MeV within its first year of operation. Thanks to the very wide energy range covered by Fermi's Gamma-ray Burst Monitor (GBM;…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Jonathan Granot

A substantial fraction of prompt GRB spectra have soft spectral indexes exceeding the maximum allowed by the synchrotron model alpha_{max}=-2/3. Some spectra also exhibit very sharp break at E_p, inconsistent with the smooth synchrotron…

Astrophysics · Physics 2009-11-10 Mikhail V. Medvedev

The emission mechanism during the prompt phase in gamma-ray bursts (GRBs) can be investigated through correlations between spectral properties. Here, we revisit the correlation relating the instantaneous flux, $F$, and the photon index…

High Energy Astrophysical Phenomena · Physics 2019-01-16 Felix Ryde , Hoi-Fung Yu , Hüsne Dereli-Bégué , Christoffer Lundman , Asaf Pe'er , Liang Li

Time-resolved spectral analysis, though a very promising method to understand the emission mechanism of gamma-ray bursts (GRBs), is difficult to implement in practice because of poor statistics. We present a new method for pulse-wise…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Rupal Basak , A. R. Rao

Growing evidence indicates that the synchrotron radiation mechanism may be responsible for the prompt emission of gamma-ray bursts (GRBs). In the synchrotron radiation scenario, the electron energy spectrum of the prompt emission is diverse…

High Energy Astrophysical Phenomena · Physics 2021-04-21 Kuan Liu , Da-Bin Lin , Jing Li , Yu-Fei Li , Rui-Jing Lu , En-Wei Liang