English
Related papers

Related papers: GRB spectral parameters within the fireball model

200 papers

Cosmic rays accelerated by a shock form a streaming distribution of outgoing particles in the foreshock region. If the ambient fields are negligible compared to the shock and cosmic ray energetics, a stronger magnetic field can be generated…

Astrophysics · Physics 2011-02-11 Mikhail V. Medvedev , Olga V. Zakutnyaya

Gamma Ray Bursts (GRBs) show evidence of different light curves, duration, afterglows, host galaxies and they explode within a wide redshift range. However, their spectral energy distributions (SEDs) appear to be very similar showing a…

High Energy Astrophysical Phenomena · Physics 2015-05-27 F. Massaro , J. E. Grindlay

We show that the relativistic two-stream instability can naturally generate strong magnetic fields with 1e-5 - 1e-1 of the equipartition energy density, in the collisionless shocks of Gamma-Ray-Burst (GRB) sources. The generated fields are…

Astrophysics · Physics 2009-10-31 Mikhail V. Medvedev , Abraham Loeb

Using the modified internal shock wave model we fit the gamma ray burst (GRB) light and spectral curves of 30 GRBs observed with BATSE. From the best fitting we obtain basic parameters of the relativistic shells which are in good agreement…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Sasa Simić , Luka Č. Popović

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

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

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

There are about 2000 gamma ray burst (GRB) events known to us with data pouring in at the rate of one per day. While the afterglows of GRBs in radio, optical and X-ray bands are successfully explained by the fireball model, a significant…

Astrophysics · Physics 2007-05-23 Jishnu Dey , Subharthi Ray , Xiang-Dong Li , Mira Dey , Ignazio Bombaci

The standard model of GRB afterglows assumes that the radiation observed as a delayed emission is of synchrotron origin, which requires the shock magnetic field to be relatively homogeneous on small scales. An alternative mechanism --…

Astrophysics · Physics 2011-02-11 Mikhail V. Medvedev , Davide Lazzati , Brian C. Morsony , Jared C. Workman

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

Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks e.g. gamma-ray bursts (GRBs) active galactic nuclei (AGNs) and microquasars commonly exhibit power-law emission spectra. Recent PIC simulations…

Astrophysics · Physics 2009-06-23 K. -I. Nishikawa , P. Hardee , Y. Mizuno , M. Medvedev , B. Zhang , D. H. Hartmann , G. J. Fishman

In this work we numerically calculate the thermal radiation efficiency of the baryonic outflow. The possible outflow acceleration in the transparent stage, which lowers thermal radiation efficiency, has been taken into account. In the…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-07 Yi-Zhong Fan

We test the models of synchrotron emission presented in Part I of this series (Lloyd & Petrosian, these proceedings) against the distributions and evolution of GRB spectral parameters (particularly the low energy index, $\alpha$). With…

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

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

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 consider a model in which the ultra-relativistic jet in a gamma-ray burst (GRB) is cold and magnetically accelerated. We assume that the energy flux in the outflowing material is partially thermalized via internal shocks or a reverse…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Ramesh Narayan , Pawan Kumar , Alexander Tchekhovskoy

Observations suggest that gamma-ray bursts (GRBs) are produced by the dissipation of the kinetic energy of a relativistic fireball. In this talk, recent work on the production of high energy neutrinos by GRB fireballs is reviewed. A…

High Energy Physics - Phenomenology · Physics 2009-10-31 Eli Waxman

Using a theoretical model describing pulse shapes, we have clarified the relations between the observed pulses and their corresponding timescales, such as the angular spreading time, the dynamic time as well as the cooling time. We find…

Astrophysics · Physics 2008-11-26 Zhibin Zhang , G. Z. Xie , J. G. Deng , B. T. Wei

The observational diversity of optical emission, which coincides with prompt gamma-ray bursts (GRBs), has been discovered in the recent Swift era. We show that on the assumption of the synchrotron radiation for the observed energy range…

Astrophysics · Physics 2009-11-13 Hirotsugu Doi , Kentaro Takami , Ryo Yamazaki

It is proposed that the prompt emission observed in bursts that exhibit a thermal component originates from relativistic radiation mediated shocks that form below the photosphere of the GRB outflow. It is argue that such shocks are expected…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Omer Bromberg , Ziv Mikolitzky , Amir Levinson