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Related papers: On the synchrotron spectrum of GRB prompt emission

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Particle acceleration is a fundamental process in many high-energy astrophysical environments and determines the spectral features of their synchrotron emission. We have studied the adiabatic stochastic acceleration (ASA) of electrons…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Siyao Xu

The typical spectrum of the prompt emission of gamma-ray bursts (GRBs) indicates that the electron cooling is suppressed in spite of the strong magnetic field in the standard synchrotron model. Recent Particle-in-Cell simulations show that…

High Energy Astrophysical Phenomena · Physics 2022-07-07 Ryota Goto , Katsuaki Asano

Information on the spectral shape of prompt emission in gamma-ray bursts (GRB) is mostly available only at energies $\gtrsim10$ keV, where the main instruments for GRB detection are sensitive. The origin of this emission is still very…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Gor Oganesyan , Lara Nava , Giancarlo Ghirlanda , Andrea Melandri , Annalisa Celotti

The prompt emission of most gamma-ray bursts (GRBs) typically exhibits a non-thermal Band component. The synchrotron radiation in the popular internal shock model is generally put forward to explain such a non-thermal component. However,…

High Energy Astrophysical Phenomena · Physics 2021-09-17 Kai Wang , Zi-Gao Dai

The low-energy spectra of gamma-ray bursts' (GRBs) prompt emission are closely related to the energy distribution of electrons, which is further regulated by their cooling processes. We develop a numerical code to calculate the evolution of…

High Energy Astrophysical Phenomena · Physics 2018-01-16 Jin-Jun Geng , Yong-Feng Huang , Xue-Feng Wu , Bing Zhang , Hong-Shi Zong

The radiative process responsible for gamma-Ray Burst (GRB) prompt emission has not been identified yet. If dominated by fast-cooling synchrotron radiation, the part of the spectrum immediately below the $\nu F_\nu$ peak energy should…

High Energy Astrophysical Phenomena · Physics 2017-09-20 Gor Oganesyan , Lara Nava , Giancarlo Ghirlanda , Annalisa Celotti

This work is a continuation of a previous effort (Panaitescu 2019) to study the cooling of relativistic electrons through radiation (synchrotron and self-Compton) emission and adiabatic losses, with application to the spectra and…

High Energy Astrophysical Phenomena · Physics 2022-10-26 A. D. Panaitescu , W. T. Vestrand

(abridged)Prompt GRB emission is often interpreted as synchrotron radiation from high-energy electrons accelerated in internal shocks. Fast synchrotron cooling predicts that the photon index below the spectral peak is alpha=-3/2. This…

High Energy Astrophysical Phenomena · Physics 2015-05-19 F. Daigne , Z. Bosnjak , Guillaume Dubus

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

Growing evidence indicates that the synchrotron radiation mechanism may be responsible for the prompt emission of gamma-ray bursts (GRBs). In the synchrotron radiation scenario, the electron energy spectrum of the prompt emission is diverse…

High Energy Astrophysical Phenomena · Physics 2021-04-21 Kuan Liu , Da-Bin Lin , Jing Li , Yu-Fei Li , Rui-Jing Lu , En-Wei Liang

Gamma-ray Bursts (GRBs) prompt emission spectra are often fitted with the empirical ''Band" function, namely two power laws smoothly connected. The typical slope of the low energy (sub-MeV) power law is $\alpha_{B}\simeq -1$. In a small…

High Energy Astrophysical Phenomena · Physics 2021-08-25 M. Toffano , G. Ghirlanda , L. Nava , G. Ghisellini , M. E. Ravasio , G. Oganesyan

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

Detection of prompt emission by Swift-XRT provides a unique tool to study how the prompt spectrum of gamma-ray bursts (GRBs) extends down to the soft X-ray band. This energy band is particularly important for prompt emission studies, since…

High Energy Astrophysical Phenomena · Physics 2018-09-05 Gor Oganesyan , Lara Nava , Giancarlo Ghirlanda , Annalisa Celotti

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

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 prompt-emission spectra of gamma-ray bursts (GRBs) are commonly described by the empirical Band function. The typical low-energy spectral index is $\sim -1$, which poses a challenge to standard synchrotron radiation models. We…

High Energy Astrophysical Phenomena · Physics 2026-04-23 Jia-Ming Chen , Ke-Rui Zhu , Zhao-Yang Peng , Yong-Gang Zheng , Yun-Lu Gong , Shan Chang , Shi-Ting Tian , Li Zhang

The emission mechanism of the gamma-ray bursts (GRBs) is still a matter of debates. The standard synchrotron energy spectrum of cooling electrons F_E ~ E^{-1/2} is much too soft to account for the majority of the observed spectral slopes.…

Astrophysics · Physics 2009-11-10 Boris E. Stern , Juri Poutanen

We discuss the synchrotron emission of fast cooling electrons in shocks. The fast cooling electrons behind the shocks can generate a position-dependent inhomogeneous electron distribution if they do not have enough time to mix…

High Energy Astrophysical Phenomena · Physics 2017-04-27 Xiao-hong Zhao , Jin-ming Bai

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

Under the steady state condition, the spectrum of electrons is investigated by solving the continuity equation under the complex radiation of both the synchrotron and Compton processes. The resulted GRB spectrum is a broken power law in…

High Energy Astrophysical Phenomena · Physics 2016-06-13 Yunguo Jiang , Shao-Ming Hu , Xu Chen , Kai Li , Di-Fu Guo , Yu-Tong Li , Huai-Zhen Li , Hai-Nan Lin , Zhe Chang
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