Constraining the Jet Composition of GRB 221009A with the Prompt TeV Emission Limit
Recent LHAASO observations of the prompt emission phase of the brightest-of-all-time GRB 221009A imposes a stringent limit on the flux ratio between the TeV and MeV emissions, F _TeV / F _MeV ≤ 2 × 10 ^−5 , during the period 220–230 s after the trigger. This period covers the peak of the main MeV bu...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal Letters |
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| Online Access: | https://doi.org/10.3847/2041-8213/ad0720 |
| _version_ | 1797631135007637504 |
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| author | Cui-Yuan Dai Xiang-Yu Wang Ruo-Yu Liu Bing Zhang |
| author_facet | Cui-Yuan Dai Xiang-Yu Wang Ruo-Yu Liu Bing Zhang |
| author_sort | Cui-Yuan Dai |
| collection | DOAJ |
| description | Recent LHAASO observations of the prompt emission phase of the brightest-of-all-time GRB 221009A imposes a stringent limit on the flux ratio between the TeV and MeV emissions, F _TeV / F _MeV ≤ 2 × 10 ^−5 , during the period 220–230 s after the trigger. This period covers the peak of the main MeV burst and is just before the TeV afterglow emerges. Within the framework of internal shocks, we study the internal γγ absorption in GRB 221009A by generating a set of synthetic bursts in a simulation that reproduces the observed feature of GRB 221009A. We find that the γγ absorption does not lead to an exponential cutoff, but rather a power-law spectrum, consistent with previous works. We further find that the attenuation due to γγ absorption alone cannot explain the flux limit ratio of GRB 221009A, suggesting a low ratio between synchrotron self-Compton (SSC) and synchrotron emission outputs. This requires the magnetic field energy density to be much larger than the synchrotron photon energy density so that the SSC flux is greatly suppressed. This indicates that the jet composition of GRB 221009A is likely Poynting flux dominated. |
| first_indexed | 2024-03-11T11:17:25Z |
| format | Article |
| id | doaj.art-59781218b55d49eea7e4e655cd43e087 |
| institution | Directory Open Access Journal |
| issn | 2041-8205 |
| language | English |
| last_indexed | 2024-03-11T11:17:25Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal Letters |
| spelling | doaj.art-59781218b55d49eea7e4e655cd43e0872023-11-10T18:28:40ZengIOP PublishingThe Astrophysical Journal Letters2041-82052023-01-019572L3210.3847/2041-8213/ad0720Constraining the Jet Composition of GRB 221009A with the Prompt TeV Emission LimitCui-Yuan Dai0https://orcid.org/0000-0002-0170-0741Xiang-Yu Wang1https://orcid.org/0000-0002-5881-335XRuo-Yu Liu2https://orcid.org/0000-0003-1576-0961Bing Zhang3https://orcid.org/0000-0002-9725-2524School of Astronomy and Space Science, Nanjing University , Nanjing 210093, People's Republic of China ; xywang@nju.edu.cn, ryliu@nju.edu.cn; Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University) , Ministry of Education, Nanjing 210093, People's Republic of ChinaSchool of Astronomy and Space Science, Nanjing University , Nanjing 210093, People's Republic of China ; xywang@nju.edu.cn, ryliu@nju.edu.cn; Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University) , Ministry of Education, Nanjing 210093, People's Republic of ChinaSchool of Astronomy and Space Science, Nanjing University , Nanjing 210093, People's Republic of China ; xywang@nju.edu.cn, ryliu@nju.edu.cn; Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University) , Ministry of Education, Nanjing 210093, People's Republic of ChinaNevada Center for Astrophysics, University of Nevada , Las Vegas, NV 89154, USA ; bing.zhang@unlv.edu; Department of Physics and Astronomy, University of Nevada Las Vegas , Las Vegas, NV 89154, USARecent LHAASO observations of the prompt emission phase of the brightest-of-all-time GRB 221009A imposes a stringent limit on the flux ratio between the TeV and MeV emissions, F _TeV / F _MeV ≤ 2 × 10 ^−5 , during the period 220–230 s after the trigger. This period covers the peak of the main MeV burst and is just before the TeV afterglow emerges. Within the framework of internal shocks, we study the internal γγ absorption in GRB 221009A by generating a set of synthetic bursts in a simulation that reproduces the observed feature of GRB 221009A. We find that the γγ absorption does not lead to an exponential cutoff, but rather a power-law spectrum, consistent with previous works. We further find that the attenuation due to γγ absorption alone cannot explain the flux limit ratio of GRB 221009A, suggesting a low ratio between synchrotron self-Compton (SSC) and synchrotron emission outputs. This requires the magnetic field energy density to be much larger than the synchrotron photon energy density so that the SSC flux is greatly suppressed. This indicates that the jet composition of GRB 221009A is likely Poynting flux dominated.https://doi.org/10.3847/2041-8213/ad0720Gamma-ray burstsHigh energy astrophysicsNon-thermal radiation sourcesRadiative transfer |
| spellingShingle | Cui-Yuan Dai Xiang-Yu Wang Ruo-Yu Liu Bing Zhang Constraining the Jet Composition of GRB 221009A with the Prompt TeV Emission Limit The Astrophysical Journal Letters Gamma-ray bursts High energy astrophysics Non-thermal radiation sources Radiative transfer |
| title | Constraining the Jet Composition of GRB 221009A with the Prompt TeV Emission Limit |
| title_full | Constraining the Jet Composition of GRB 221009A with the Prompt TeV Emission Limit |
| title_fullStr | Constraining the Jet Composition of GRB 221009A with the Prompt TeV Emission Limit |
| title_full_unstemmed | Constraining the Jet Composition of GRB 221009A with the Prompt TeV Emission Limit |
| title_short | Constraining the Jet Composition of GRB 221009A with the Prompt TeV Emission Limit |
| title_sort | constraining the jet composition of grb 221009a with the prompt tev emission limit |
| topic | Gamma-ray bursts High energy astrophysics Non-thermal radiation sources Radiative transfer |
| url | https://doi.org/10.3847/2041-8213/ad0720 |
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