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Related papers: GRB physics with Fermi

200 papers

In recent years, our understanding of gamma-ray bursts (GRB) prompt emission has been revolutionized, due to a combination of new instruments, new analysis methods and novel ideas. In this review, I describe the most recent observational…

High Energy Astrophysical Phenomena · Physics 2015-09-23 Asaf Pe'er

The photospheric emission in the prompt phase is the natural prediction of the original fireball model for gamma-ray burst (GRB) due to the large optical depth ($\tau >1$) at the base of the outflow, which is supported by the quasi-thermal…

High Energy Astrophysical Phenomena · Physics 2021-12-02 Yan-Zhi Meng , Jin-Jun Geng , Xue-Feng Wu

Swift-XRT observations of the X-ray emission from gamma ray bursts (GRBs) and during the GRB afterglow have led to many new results during the past two years. One of these exciting results is that approximately 1/3-1/2 of GRBs contain…

Previous studies have considered synchrotron as the emission mechanism for prompt Gamma-Ray Bursts (GRBs). These works have shown that the electrons must cool on a timescale comparable to the dynamic time at the source in order to satisfy…

High Energy Astrophysical Phenomena · Physics 2018-02-28 Paz Beniamini , Rodolfo Barniol Duran , Dimitrios Giannios

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

This paper introduces a kinetic code that simulates gamma-ray burst (GRB) afterglow emission from the external forward shock and presents examples of some of its applications. One interesting research topic discussed in the paper is the…

High Energy Astrophysical Phenomena · Physics 2014-09-24 T. Pennanen , I. Vurm , J. Poutanen

The study of the high-energy (MeV-GeV) part of GRBs spectrum can play a crucial role in investigating the physics of the prompt emission, but it is often hampered by low statistic and the paucity of GeV observations. In this work, we…

High Energy Astrophysical Phenomena · Physics 2024-05-29 M. E. Ravasio , G. Ghirlanda , G. Ghisellini

We analyze the >100MeV data for 3 GRBs detected by Fermi (GRBs 080916C, 090510, 090902B) and find that these photons were generated via synchrotron emission in the external forward shock. We arrive at this conclusion by four different…

High Energy Astrophysical Phenomena · Physics 2010-12-13 Pawan Kumar , Rodolfo Barniol Duran

Observations by the {\RHESSI} satellite of large polarization of the prompt $\gamma$-ray emission from the Gamma Ray Burst GRB021206 \citep{coburn03} imply that the magnetic field coherence scale is larger than the size of the visible…

Astrophysics · Physics 2009-11-07 Maxim Lyutikov , V. I. Pariev , Roger Blandford

In the framework of the internal shock scenario, we model the broadband prompt emission of gamma-ray bursts (GRBs) with emphasis on the GeV-TeV bands, utilizing Monte Carlo simulations that include various processes associated with…

Astrophysics · Physics 2009-06-23 Katsuaki Asano , Susumu Inoue

The physics of GRB powered by a magnetic energy flux is reviewed. Magnetic fields are natural for transmitting the energy from the central compact object to the small amount of baryons required for a GRB. When dissipation of the flux of…

Astrophysics · Physics 2007-05-23 H. C. Spruit , G. Drenkhahn

The origin of prompt emission in $\gamma$-ray bursts (GRBs) is highly debated topic. The observed spectra are supposed to play a crucial role in constraining the location of the emitting region, the strength of the magnetic field and the…

High Energy Astrophysical Phenomena · Physics 2020-06-26 Gor Oganesyan

Binary neutron star mergers are considered to be the most favorable sources that produce electromagnetic (EM) signals associated with gravitational waves (GWs). These mergers are the likely progenitors of short duration gamma-ray bursts…

High Energy Astrophysical Phenomena · Physics 2017-10-26 Adithan Kathirgamaraju , Rodolfo Barniol Duran , Dimitrios Giannios

Gamma-ray bursts (GRBs) are a mixed class of sources consisting of, at least, the long duration and short-hard subclasses, the X-ray flashes, and the low-luminosity GRBs. In all cases, the release of enormous amounts of energy on a short…

Astrophysics · Physics 2008-09-24 Charles D. Dermer , Chris L. Fryer

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…

We report on the multiwavelength observations of the bright, long gamma-ray burst \GRB, by the \Fermi and \Swift observatories, and by the MOA and GROND optical telescopes. The analysis of the prompt phase reveals that \GRB shares many…

High Energy Astrophysical Phenomena · Physics 2013-01-11 LAT Collaboration , GBM Collaboration , Swift Collaboration , GROND Collaboration , the MOA Collaboration

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…

The high-energy (> 100MeV) emission observed by Fermi-LAT during the prompt phase of some luminous gamma-ray bursts (GRBs) could arise from the cascade induced by interactions between accelerated protons and the radiation field of GRBs. The…

High Energy Astrophysical Phenomena · Physics 2018-04-25 Kai Wang , Ruo-Yu Liu , Zi-Gao Dai , Katsuaki Asano

We argue that small pitch angle synchrotron emission provides an important dissipation mechanism which has to be taken into account in the models of formation of relativistic magnetized gamma-ray burst (GRB) outflows from the newborn black…

High Energy Astrophysical Phenomena · Physics 2010-08-12 A. Neronov , V. Savchenko

Using a detailed model of the internal shock phase, we discuss the origin of the prompt emission in gamma-ray bursts. We focus on the identification of the dominant radiative process (Fermi-GBM range) and propose an explanation for some…

High Energy Astrophysical Phenomena · Physics 2009-12-21 F. Daigne , Z. Bosnjak , G. Dubus