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Related papers: Radiation Processes in GRBs. Prompt Emission

200 papers

We discuss here constraints on the particle acceleration models from the observed gamma-ray bursts spectra. The standard synchrotron shock model assumes that some fraction of available energy is given instantaneously to the electrons which…

Astrophysics · Physics 2010-11-11 Juri Poutanen , Boris E. Stern

We investigate synchrotron emission models as the source of gamma ray burst spectra. We show that allowing for synchrotron self absorption and a ``smooth cutoff'' to the electron energy distribution produces a wide range of low energy…

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

The mechanism that causes the prompt-emission episode of gamma-ray bursts (GRBs) is still widely debated despite there being thousands of prompt detections. The favoured internal shock model relates this emission to synchrotron radiation.…

There is no consensus on the emission mechanism of $\gamma$-ray bursts (GRBs). A synchrotron model can produce $\gamma$-ray spectra with the empirical Band function form, from a piece-wise two-power-law electron energy distribution (2EPLS).…

High Energy Astrophysical Phenomena · Physics 2019-09-06 Bruce Grossan , Pawan Kumar , George F. Smoot

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

Gamma-ray bursts (GRBs) are among the most luminous sources in the universe. The nature of their emission at TeV energies is one of the most relevant open issues related to these events. The temporal and spectral features inferred from the…

High Energy Astrophysical Phenomena · Physics 2021-08-10 Y. Pérez Araujo , M. M. González , N. Fraija

The origin of rapid spectral variability and certain spectral correlations of the prompt gamma-ray burst emission remains an intriguing question. The recently proposed theoretical model of the prompt emission is build upon unique spectral…

High Energy Astrophysical Phenomena · Physics 2009-08-24 Mikhail V. Medvedev , Sriharsha S. Pothapragada , Sarah J. Reynolds

We present detailed calculations of the prompt spectrum of gamma-ray bursts (GRBs) predicted within the fireball model framework, where emission is due to internal shocks in an expanding relativistic wind. Our time dependent numerical model…

Astrophysics · Physics 2014-10-13 Asaf Pe'er , Eli Waxman

The emission processes active in the highly relativistic jets of gamma-ray bursts (GRBs) remain unknown. In this paper we propose a new measure to describe spectra: the width of the $EF_E$ spectrum, a quantity dependent only on finding a…

High Energy Astrophysical Phenomena · Physics 2015-01-20 Magnus Axelsson , Luis Borgonovo

Internal shocks are a leading candidate for the dissipation mechanism that powers the prompt $\gamma$-ray emission in gamma-ray bursts (GRBs). In this scenario a compact central source produces an ultra-relativistic outflow with varying…

High Energy Astrophysical Phenomena · Physics 2023-12-25 Sk. Minhajur Rahaman , Jonathan Granot , Paz Beniamini

The brightest Gamma-ray burst, GRB 221009A, has spurred numerous theoretical investigations, with particular attention paid to the origins of ultra-high energy TeV photons during the prompt phase. However, analyzing the mechanism of…

We constrain the distance of the Gamma-Ray Burst (GRB) prompt emission site from the explosion centre, R, by determining the location of the electron's self absorption frequency in the GRB prompt optical-to-X/gamma-ray spectral energy…

High Energy Astrophysical Phenomena · Physics 2014-03-11 Rong-Feng Shen , Bing Zhang

The prompt emission of Gamma Ray Bursts (GRBs) is still an outstanding question in the study of these cataclysmic events. Part of what makes GRBs difficult to study is how unique each event seems to be. However, aggregating many GRB…

High Energy Astrophysical Phenomena · Physics 2022-05-31 Tyler Parsotan , Hirotaka Ito

The principal paradigm for gamma-ray bursts (GRBs) suggests that the prompt transient gamma-ray signal arises from multiple shocks internal to the relativistic expansion. This paper explores how GRB prompt emission spectra can constrain…

High Energy Astrophysical Phenomena · Physics 2009-06-25 Matthew G. Baring

The emission process responsible for the so-called "prompt" emission of gamma-ray bursts is still unknown. A number of empirical models fitting the typical spectrum still lack a satisfactory interpretation. A few GRB spectral catalogues…

High Energy Astrophysical Phenomena · Physics 2011-05-03 C. Guidorzi , M. Lacapra , F. Frontera , E. Montanari , L. Amati , F. Calura , L. Nicastro , M. Orlandini

The robotic ROTSE-III telescope network detected prompt optical emission contemporaneous with the gamma-ray emission of Swift events GRB051109A and GRB051111. Both datasets have continuous coverage at high signal-to-noise levels from the…

Gamma-ray bursts (GRBs) are the universe's most energetic phenomena (isotropic luminosity $\sim 10^{51} - 10^{54}$ ergs/s) lasting for a very short duration ($\sim$ milliseconds - a few seconds). Even after an average of one GRB detected…

High Energy Astrophysical Phenomena · Physics 2026-05-13 Soumya Gupta , Sunder Sahayanathan , Saharsh Shanu , Rishabh Nath

The debate regarding the emission mechanism in gamma-ray bursts has been long-standing. Here, we study the spectral signatures of photospheric emission, accounting for subphotospheric dissipation by a radiation-mediated shock. The shocks…

High Energy Astrophysical Phenomena · Physics 2024-07-15 Filip Alamaa , Felix Ryde , Christoffer Lundman

Early X-ray emission of Gamma-Ray Bursts (GRBs) traces the transition between the prompt emission and the afterglow radiation, and its rapid flux decline is often interpreted as the tail of the prompt emission. As such, it can offer…

High Energy Astrophysical Phenomena · Physics 2026-04-08 Annarita Ierardi , Gor Oganesyan , Stefano Ascenzi , Marica Branchesi , Biswajit Banerjee , Samuele Ronchini

The dominant radiation mechanism that produces the prompt emission in gamma-ray bursts (GRBs) remains a major open question. Spectral information alone has proven insufficient in elucidating its nature. Time-resolved linear polarization has…

High Energy Astrophysical Phenomena · Physics 2021-04-21 Ramandeep Gill , Jonathan Granot