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Related papers: Gamma-ray burst internal shocks with magnetization

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Synchrotron radiation from accelerated electrons above the photosphere of a relativistic ejecta is a natural candidate for the dominant process for the prompt GRB emission. There is however a tension between the predicted low-energy…

High Energy Astrophysical Phenomena · Physics 2025-01-29 Frédéric Daigne , Željka Bošnjak

Gamma-ray bursts (GRBs) are powered by relativistic jets that exhibit intermittency over a broad range of timescales - from $ \sim $ ms to seconds. Previous numerical studies have shown that hydrodynamic (i.e., unmagnetized) jets that are…

High Energy Astrophysical Phenomena · Physics 2021-04-28 Ore Gottlieb , Omer Bromberg , Amir Levinson , Ehud Nakar

Relativistic magnetized shocks are a natural source of coherent emission, offering a plausible radiative mechanism for Fast Radio Bursts (FRBs). We present first-principles 3D simulations that provide essential information for the FRB…

High Energy Astrophysical Phenomena · Physics 2021-07-28 Lorenzo Sironi , Illya Plotnikov , Joonas Nättilä , Andrei M. Beloborodov

We present a systematic study on magnetic fields in Gamma-Ray Burst (GRB) external forward shocks (FSs). There are 60 (35) GRBs in our X-ray (optical) sample, mostly from Swift. We use two methods to study epsilon_B (fraction of energy in…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Rodolfo Santana , Rodolfo Barniol Duran , Pawan Kumar

The composition of gamma-ray burst (GRB) jets remained a mystery until recently. In practice, we usually characterize the magnetization of the GRB jets ($\sigma_0$) through the ratio between the Poynting flux and matter (baryonic) flux.…

High Energy Astrophysical Phenomena · Physics 2024-08-05 An Li , He Gao , Lin Lan , Bing Zhang

Gamma-ray bursts detected at high energies provide valuable insights into the emission mechanisms behind these still puzzling enigmatic events. In this study, we focus on GRB 090510, which is an unusual short GRB exhibiting plateau emission…

High Energy Astrophysical Phenomena · Physics 2025-02-07 Joseph Saji , Agnieszka Janiuk , Maria Giovanna Dainotti , Shubham Bhardwaj , Gerardo Urrutia

We present an analysis of the Internal Shock Model of GRBs, where gamma-rays are produced by internal shocks within a relativistic wind. We show that observed GRB characteristics impose stringent constraints on wind and source parameters.…

Astrophysics · Physics 2009-10-31 D. Guetta , M. Spada , E. Waxman

GRB 120308A, a long duration $\gamma-$ray burst detected by {\it Swift}, was distinguished by a highly-polarized early optical afterglow emission that strongly suggests an ordered magnetic field component in the emitting region. In this…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Shuai Zhang , Zhi-Ping Jin , Da-Ming Wei

We investigate the dynamics and radiation from a relativistic blast-wave which decelerates as it sweeps up ambient matter. The bulk kinetic energy of the blast-wave shell is converted into internal energy by the process of accreting…

Astrophysics · Physics 2016-08-30 J. Chiang , C. D. Dermer

Internal-Collision-induced Magnetic Reconnection and Turbulence (ICMART) model is a widely accepted model for explaining how high-magnetization jets produce gamma-ray burst (GRB) prompt emissions. In previous works, we show that this model…

High Energy Astrophysical Phenomena · Physics 2025-12-09 Xueying Shao , He Gao

The strong variability of magnetic central engines of AGN and GRBs may result in highly intermittent strongly magnetized relativistic outflows. We find a new magnetic acceleration mechanism for such impulsive flows that can be much more…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Jonathan Granot , Serguei Komissarov , Anatoly Spitkovsky

Among the models used to explain the prompt emission of gamma-ray bursts (GRBs), internal shocks is a leading one. Its most basic ingredient is a collision between two cold shells of different Lorentz factors in an ultra-relativistic…

High Energy Astrophysical Phenomena · Physics 2025-07-09 A. Charlet , J. Granot , P. Beniamini

In the internal shock model for gamma-ray bursts (GRBs), the synchrotron spectrum from the fast cooling electrons in a homogeneous downstream magnetic field (MF) is too soft to produce the low-energy slope of GRB spectra. However the…

High Energy Astrophysical Phenomena · Physics 2015-06-17 X. H. Zhao , Z. Li , X. W. Liu , B. B. Zhang , J. M. Bai , P. Meszaros

We describe our attempt to determine if gamma-ray burst (GRB) and afterglow emissions could both arise in external shocks for simple GRBs--bursts consisting of just a few peaks in their lightcurves. We calculate peak flux and peak frequency…

Astrophysics · Physics 2016-08-30 E. McMahon , P. Kumar , A. Panaitescu

Gamma-ray bursts observed in high-energies allow the investigation of the emission processes of these still puzzling events. In this study, we perform general relativistic magnetohydrodynamic (GRMHD) simulations to investigate GRB 090510, a…

High Energy Astrophysical Phenomena · Physics 2026-05-13 Joseph Saji , Maria Giovanna Dainotti , Shubham Bhardwaj , Agnieszka Janiuk

Gamma-ray bursts (GRBs), among the most compelling astrophysical phenomena, are potential candidates for exploring the evolution of energy distribution among magnetic fields and particles through multiwavelength observations. The fraction…

High Energy Astrophysical Phenomena · Physics 2025-12-18 Nissim Fraija , Boris Betancourt-Kamenetskaia , Antonio Galván , Maria Dainotti

Even with the renaissance in gamma-ray burst (GRB) research fostered by the Swift satellite, few bursts have both contemporaneous observations at long wavelengths and exquisite observations at later times across the electromagnetic…

The physical origin of prompt emission in gamma-ray bursts (GRBs) remains an open question since it has been studied more than half a century. Three alternative models (i.e. dissipative photosphere, internal shock, and…

High Energy Astrophysical Phenomena · Physics 2025-11-27 Yang-Dong-Jun Ou , Hou-Jun Lü , Jia-Ming Chen , Ben-Yang Zhu , En-Wei Liang

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

Relativistic magnetohydrodynamic shocks are efficient particle accelerators, often invoked in the models of gamma-ray bursts (GRBs) and shock-powered fast radio bursts (FRBs). Most theoretical studies assume a perpendicular shock with an…

High Energy Astrophysical Phenomena · Physics 2022-01-19 Jing-Ze Ma , Bing Zhang