Radiation Spectrum of the Photospheric Emission for a Turbulent Relativistic Jet

The prompt gamma rays of gamma-ray bursts (GRBs) may originate from the photosphere of a relativistic jet. However, only a few GRBs have been observed with evident blackbody-like emission, for example, GRB 090902B. It has been demonstrated that internal dissipation processes, such as magnetic reconn...

Full description

Saved in:
Bibliographic Details
Main Authors: Guo-Yu Li, Da-Bin Lin, Zhi-Lin Chen, En-Wei Liang
Format: Article
Language:English
Published: IOP Publishing 2025-01-01
Series:The Astrophysical Journal
Subjects:
Online Access:https://doi.org/10.3847/1538-4357/adf21e
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850033464773967872
author Guo-Yu Li
Da-Bin Lin
Zhi-Lin Chen
En-Wei Liang
author_facet Guo-Yu Li
Da-Bin Lin
Zhi-Lin Chen
En-Wei Liang
author_sort Guo-Yu Li
collection DOAJ
description The prompt gamma rays of gamma-ray bursts (GRBs) may originate from the photosphere of a relativistic jet. However, only a few GRBs have been observed with evident blackbody-like emission, for example, GRB 090902B. It has been demonstrated that internal dissipation processes, such as magnetic reconnection, can occur within the relativistic jet and thereby drive violent turbulence in the dissipation region. In this paper, we study the photospheric emission of a jet with turbulence below its photosphere. Here, the turbulence is modeled phenomenologically under the assumption that the four-velocity of its eddies follows a Gaussian distribution in the jet’s comoving frame. It is found that the turbulence scatters photons to high energies and thus intensifies the emission in the high-energy regime. The corresponding distortion of the radiation field can be preserved if and only if the turbulence occurs in a region with incomplete photon–electron coupling. Consequently, the observed radiation spectrum can be reshaped into a Band-like spectrum.
format Article
id doaj-art-66d2aec5b2f54780ada8e55fbceda76b
institution DOAJ
issn 1538-4357
language English
publishDate 2025-01-01
publisher IOP Publishing
record_format Article
series The Astrophysical Journal
spelling doaj-art-66d2aec5b2f54780ada8e55fbceda76b2025-08-20T02:58:11ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01989214510.3847/1538-4357/adf21eRadiation Spectrum of the Photospheric Emission for a Turbulent Relativistic JetGuo-Yu Li0https://orcid.org/0000-0002-6727-7798Da-Bin Lin1https://orcid.org/0000-0003-1474-293XZhi-Lin Chen2https://orcid.org/0000-0002-0926-5406En-Wei Liang3https://orcid.org/0000-0002-7044-733XGuangxi Key Laboratory for Relativistic Astrophysics, School of Physical Science and Technology, Guangxi University , Nanning 530004, People’s Republic of China ; lindabin@gxu.edu.cnGuangxi Key Laboratory for Relativistic Astrophysics, School of Physical Science and Technology, Guangxi University , Nanning 530004, People’s Republic of China ; lindabin@gxu.edu.cnGuangxi Key Laboratory for Relativistic Astrophysics, School of Physical Science and Technology, Guangxi University , Nanning 530004, People’s Republic of China ; lindabin@gxu.edu.cnGuangxi Key Laboratory for Relativistic Astrophysics, School of Physical Science and Technology, Guangxi University , Nanning 530004, People’s Republic of China ; lindabin@gxu.edu.cnThe prompt gamma rays of gamma-ray bursts (GRBs) may originate from the photosphere of a relativistic jet. However, only a few GRBs have been observed with evident blackbody-like emission, for example, GRB 090902B. It has been demonstrated that internal dissipation processes, such as magnetic reconnection, can occur within the relativistic jet and thereby drive violent turbulence in the dissipation region. In this paper, we study the photospheric emission of a jet with turbulence below its photosphere. Here, the turbulence is modeled phenomenologically under the assumption that the four-velocity of its eddies follows a Gaussian distribution in the jet’s comoving frame. It is found that the turbulence scatters photons to high energies and thus intensifies the emission in the high-energy regime. The corresponding distortion of the radiation field can be preserved if and only if the turbulence occurs in a region with incomplete photon–electron coupling. Consequently, the observed radiation spectrum can be reshaped into a Band-like spectrum.https://doi.org/10.3847/1538-4357/adf21eGamma-ray burstsHigh energy astrophysics
spellingShingle Guo-Yu Li
Da-Bin Lin
Zhi-Lin Chen
En-Wei Liang
Radiation Spectrum of the Photospheric Emission for a Turbulent Relativistic Jet
The Astrophysical Journal
Gamma-ray bursts
High energy astrophysics
title Radiation Spectrum of the Photospheric Emission for a Turbulent Relativistic Jet
title_full Radiation Spectrum of the Photospheric Emission for a Turbulent Relativistic Jet
title_fullStr Radiation Spectrum of the Photospheric Emission for a Turbulent Relativistic Jet
title_full_unstemmed Radiation Spectrum of the Photospheric Emission for a Turbulent Relativistic Jet
title_short Radiation Spectrum of the Photospheric Emission for a Turbulent Relativistic Jet
title_sort radiation spectrum of the photospheric emission for a turbulent relativistic jet
topic Gamma-ray bursts
High energy astrophysics
url https://doi.org/10.3847/1538-4357/adf21e
work_keys_str_mv AT guoyuli radiationspectrumofthephotosphericemissionforaturbulentrelativisticjet
AT dabinlin radiationspectrumofthephotosphericemissionforaturbulentrelativisticjet
AT zhilinchen radiationspectrumofthephotosphericemissionforaturbulentrelativisticjet
AT enweiliang radiationspectrumofthephotosphericemissionforaturbulentrelativisticjet