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Related papers: GRB spectral parameter modeling

200 papers

We consider possible geometries of magnetic fields in GRB outflows, and their evolution with distance from the source. For magnetically driven outflows, with an assumed ratio of magnetic to kinetic energy density of order unity, the field…

Astrophysics · Physics 2009-10-31 H. C. Spruit , F. Daigne , G. Drenkhahn

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

The radiation from afterglows of gamma-ray bursts is generated in the collisionless plasma shock interface between a relativistic outflow and a quiescent circum-burst medium. The two main ingredients responsible for the radiation are…

Astrophysics · Physics 2007-05-23 Christian Busk Hededal , Åke Nordlund

We introduce a non-resonant acceleration mechanism arising from the second adiabatic invariant in magnetic turbulence and apply it to study the prompt emission spectra of gamma-ray bursts (GRBs). The mechanism contains both the first- and…

High Energy Astrophysical Phenomena · Physics 2017-09-20 Siyao Xu , Bing Zhang

Synchrotron radiation of relativistic electrons is an important radiation mechanism in many astrophysical sources. In the sources where the synchrotron cooling time scale $t_c$ is shorter than the dynamical time scale $t_{dyn}$, electrons…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Z. Lucas Uhm , Bing Zhang

The cosmological gamma-ray burst (GRB) phenomenon is reviewed. The broad observational facts and empirical phenomenological relations of the GRB prompt emission and afterglow are outlined. A well-tested, successful fireball shock model is…

Astrophysics · Physics 2007-05-23 Bing Zhang , Peter Meszaros

The spectral shape of the prompt emissions of gamma-ray bursts (GRBs) is typically expressed by the Band function: smooth joining of two power-law functions for high-energy and low-energy regions. To reveal the origin of the Band function,…

High Energy Astrophysical Phenomena · Physics 2015-10-21 Katsuaki Asano , Toshio Terasawa

Afterglows of GRBs are, in general, well described by the fireball model. Yet, deducing the full set of model parameters from observations without prior assumptions has been possible for only a handful of GRBs. With GROND, a 7-channel…

High Energy Astrophysical Phenomena · Physics 2025-09-03 Karla Varela , Jochen Greiner , Patricia Schady , Hendrik van Eerten

Fast radio bursts (FRB) can arise from synchrotron maser emission at ultra-relativistic magnetized shocks, such as produced by flare ejecta from young magnetars. We combine PIC simulation results for the synchrotron maser with the dynamics…

High Energy Astrophysical Phenomena · Physics 2019-04-10 Brian D. Metzger , Ben Margalit , Lorenzo Sironi

Gamma-ray Bursts (GRBs) generate powerful relativistic jets that inject a large amount of energy into their surrounding environment, producing blast waves that accelerate particles to high energies. The GRB afterglow radiation provides a…

High Energy Astrophysical Phenomena · Physics 2026-02-24 P. Tiwari , B. Banerjee , D. Miceli , G. Oganesyan , A. Ierardi , S. Macera , M. Branchesi , L. Nava , S. Mohnani , S. Agarwal , A. Shukla

I describe electromagnetic model of gamma ray bursts and contrast its main properties and predictions with hydrodynamic fireball model and its magnetohydrodynamical extension. The electromagnetic model assumes that rotational energy of a…

Astrophysics · Physics 2009-11-13 Maxim Lyutikov

We discuss the prompt emission of Gamma-Ray Bursts in different spectral energy bands. First, we suggest that a three-part synchrotron emission model is a good description of the ~20 keV - 1 MeV gamma-ray emission of GRBs. We show that this…

Astrophysics · Physics 2009-11-07 Nicole M. Lloyd-Ronning

Typical gamma-ray burst spectra are characterized by a spectral break, Ep, which for bright BATSE bursts is found to be narrowly clustered around 300 keV. Recently identified X-ray flashes, which may account for a significant portion of the…

Astrophysics · Physics 2009-11-07 Bing Zhang , Peter Meszaros

We calculate the synchrotron self-Compton emission from internal shocks occurring in relativistic winds as a source of gamma-ray bursts, with allowance for self-absorption. For plausible model parameters most pulses within a Gamma-Ray Burst…

Astrophysics · Physics 2009-10-31 A. Panaitescu , P. Meszaros

We analyze a sample of\textit{ Swift} gamma-ray bursts (GRBs) with extended emissions in $\gamma$-rays and/or X-ray plateaus that may be driven by magnetars. Multi-wavelength data and multi-standards have been adopted to investigate the…

High Energy Astrophysical Phenomena · Physics 2025-12-01 C. T. Hao , J. H. Jing , X. L. Han , H. R. Lan , W. C. Du , X. N. Liu , Z. B. Zhang , H. C. Liu , J. F. Wu , X. L. Xia

An external shock model for the prompt gamma-ray luminous phase of gamma-ray bursts (GRBs) is treated both analytically and numerically. A widely cited derivation claiming that an external shock model for rapidly variable GRBs must be very…

Astrophysics · Physics 2007-05-23 Charles D. Dermer , Kurt E. Mitman

In the hadronic fireball phenomenology of Gamma Ray Bursts (GRBs), it is expected that the observed photons are accompanied by UHE neutrinos, which have not been observed yet. It is one of the challenges of experimental UHE neutrino…

Astrophysics · Physics 2009-11-13 Julia K. Becker , Michael Stamatikos , Francis Halzen , Wolfgang Rhode

The high energy emission from Gamma-ray Bursts has some interesting features, including the absence of the GeV excess in the prompt spectrum, the delayed onset of the GeV emission, and the longer duration of the GeV emission than the prompt…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-16 Yi-Zhong Fan

The discovery of GRBs' afterglows has allowed us to establish several facts: their distance and energy scales, the fact that they are due to explosions, that the explosions are relativistic, and that the afterglow emission mechanism is…

Astrophysics · Physics 2017-08-23 Mario Vietri

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
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