Quasi-thermal Photosphere Emission from Structured Jets of Gamma-Ray Bursts
The prompt emission of gamma-ray bursts (GRBs) is supposed to be released from the relativistic jet launched from the central engine. Apart from the nonthermal nature of spectra in the majority of GRBs, there is evidence for the presence of quasi-thermal components in the prompt emission of a few GR...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/adcf20 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850231947252465664 |
|---|---|
| author | Ding-Fang Hu Jin-Jun Geng Hao-Xuan Gao Jing-Zhi Yan Xue-Feng Wu |
| author_facet | Ding-Fang Hu Jin-Jun Geng Hao-Xuan Gao Jing-Zhi Yan Xue-Feng Wu |
| author_sort | Ding-Fang Hu |
| collection | DOAJ |
| description | The prompt emission of gamma-ray bursts (GRBs) is supposed to be released from the relativistic jet launched from the central engine. Apart from the nonthermal nature of spectra in the majority of GRBs, there is evidence for the presence of quasi-thermal components in the prompt emission of a few GRBs according to observations by the Fermi satellite. On the other hand, the GRB jet has been revealed as structured in recent research. The theoretical spectra of photosphere emissions observed by an off-axis observer and the dependence of the spectra on the viewing angle under the assumption of structured jets remain unexplored. In this paper, we numerically calculate the instantaneous photosphere spectra by different viewing angles from a structured jet, from which relevant temporal and spectral characteristics are derived. Moreover, we address the necessity of proper treatment of the outflow boundary in the photosphere emission scenario. Furthermore, our calculations suggest that the Einstein Probe and Space-based Multi-band Astronomical Variable Object Monitor will have the capability to detect short GRBs similar to GRB 170817A up to a luminosity distance of 200 Mpc if the off-axis viewing angle is less than 10°. |
| format | Article |
| id | doaj-art-1b7ce096359c4748983388c074e71096 |
| institution | OA Journals |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj-art-1b7ce096359c4748983388c074e710962025-08-20T02:03:20ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-0198615710.3847/1538-4357/adcf20Quasi-thermal Photosphere Emission from Structured Jets of Gamma-Ray BurstsDing-Fang Hu0https://orcid.org/0009-0002-7851-3706Jin-Jun Geng1https://orcid.org/0000-0001-9648-7295Hao-Xuan Gao2https://orcid.org/0000-0001-7892-9790Jing-Zhi Yan3https://orcid.org/0000-0003-2553-2217Xue-Feng Wu4https://orcid.org/0000-0002-6299-1263Purple Mountain Observatory, Chinese Academy of Sciences , Nanjing 210023, People’s Republic of China ; jjgeng@pmo.ac.cn, jzyan@pmo.ac.cn, xfwu@pmo.ac.cn; School of Astronomy and Space Sciences, University of Science and Technology of China , Hefei 230026, People’s Republic of ChinaPurple Mountain Observatory, Chinese Academy of Sciences , Nanjing 210023, People’s Republic of China ; jjgeng@pmo.ac.cn, jzyan@pmo.ac.cn, xfwu@pmo.ac.cnPurple Mountain Observatory, Chinese Academy of Sciences , Nanjing 210023, People’s Republic of China ; jjgeng@pmo.ac.cn, jzyan@pmo.ac.cn, xfwu@pmo.ac.cnPurple Mountain Observatory, Chinese Academy of Sciences , Nanjing 210023, People’s Republic of China ; jjgeng@pmo.ac.cn, jzyan@pmo.ac.cn, xfwu@pmo.ac.cnPurple Mountain Observatory, Chinese Academy of Sciences , Nanjing 210023, People’s Republic of China ; jjgeng@pmo.ac.cn, jzyan@pmo.ac.cn, xfwu@pmo.ac.cn; School of Astronomy and Space Sciences, University of Science and Technology of China , Hefei 230026, People’s Republic of ChinaThe prompt emission of gamma-ray bursts (GRBs) is supposed to be released from the relativistic jet launched from the central engine. Apart from the nonthermal nature of spectra in the majority of GRBs, there is evidence for the presence of quasi-thermal components in the prompt emission of a few GRBs according to observations by the Fermi satellite. On the other hand, the GRB jet has been revealed as structured in recent research. The theoretical spectra of photosphere emissions observed by an off-axis observer and the dependence of the spectra on the viewing angle under the assumption of structured jets remain unexplored. In this paper, we numerically calculate the instantaneous photosphere spectra by different viewing angles from a structured jet, from which relevant temporal and spectral characteristics are derived. Moreover, we address the necessity of proper treatment of the outflow boundary in the photosphere emission scenario. Furthermore, our calculations suggest that the Einstein Probe and Space-based Multi-band Astronomical Variable Object Monitor will have the capability to detect short GRBs similar to GRB 170817A up to a luminosity distance of 200 Mpc if the off-axis viewing angle is less than 10°.https://doi.org/10.3847/1538-4357/adcf20Gamma-ray bursts |
| spellingShingle | Ding-Fang Hu Jin-Jun Geng Hao-Xuan Gao Jing-Zhi Yan Xue-Feng Wu Quasi-thermal Photosphere Emission from Structured Jets of Gamma-Ray Bursts The Astrophysical Journal Gamma-ray bursts |
| title | Quasi-thermal Photosphere Emission from Structured Jets of Gamma-Ray Bursts |
| title_full | Quasi-thermal Photosphere Emission from Structured Jets of Gamma-Ray Bursts |
| title_fullStr | Quasi-thermal Photosphere Emission from Structured Jets of Gamma-Ray Bursts |
| title_full_unstemmed | Quasi-thermal Photosphere Emission from Structured Jets of Gamma-Ray Bursts |
| title_short | Quasi-thermal Photosphere Emission from Structured Jets of Gamma-Ray Bursts |
| title_sort | quasi thermal photosphere emission from structured jets of gamma ray bursts |
| topic | Gamma-ray bursts |
| url | https://doi.org/10.3847/1538-4357/adcf20 |
| work_keys_str_mv | AT dingfanghu quasithermalphotosphereemissionfromstructuredjetsofgammaraybursts AT jinjungeng quasithermalphotosphereemissionfromstructuredjetsofgammaraybursts AT haoxuangao quasithermalphotosphereemissionfromstructuredjetsofgammaraybursts AT jingzhiyan quasithermalphotosphereemissionfromstructuredjetsofgammaraybursts AT xuefengwu quasithermalphotosphereemissionfromstructuredjetsofgammaraybursts |