GRB 221009A: Observations with LST-1 of CTAO and implications for structured jets in Long Gamma-Ray Bursts
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F25%3A00644401" target="_blank" >RIV/67985815:_____/25:00644401 - isvavai.cz</a>
Alternative codes found
RIV/68378271:_____/25:00644401 RIV/00216208:11320/25:10510660 RIV/61989592:15310/25:73633192
Result on the web
<a href="https://hdl.handle.net/11104/0374255" target="_blank" >https://hdl.handle.net/11104/0374255</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.3847/2041-8213/ade4cf" target="_blank" >10.3847/2041-8213/ade4cf</a>
Alternative languages
Result language
angličtina
Original language name
GRB 221009A: Observations with LST-1 of CTAO and implications for structured jets in Long Gamma-Ray Bursts
Original language description
GRB 221009A is the brightest gamma-ray burst (GRB) observed to date. Extensive observations of its afterglow emission across the electromagnetic spectrum were performed, providing the first strong evidence of a jet with a nontrivial angular structure in a long GRB. We carried out an extensive observation campaign in very-high-energy (VHE) gamma rays with the first Large-Sized Telescope of the future Cherenkov Telescope Array Observatory starting on 2022 October 10, about 1 day after the burst. A dedicated analysis of the GRB 221009A data is performed to account for the different moonlight conditions under which data were recorded. We find an excess of gamma-like events with a statistical significance of 4.1 sigma during the observations taken 1.33 days after the burst, followed by background-compatible results for the later days. The results are compared with various models of afterglows from structured jets that are consistent with the published multiwavelength data but entail significant quantitative and qualitative differences in the VHE emission after 1 day. We disfavor models that imply VHE flux at 1 day considerably above 10(-11) erg cm(-2) s(-1). Our late-time VHE observations can help disentangle the degeneracy among the models and provide valuable new insight into the structure of GRB jets.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10308 - Astronomy (including astrophysics,space science)
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Astrophysical Journal Letters
ISSN
2041-8205
e-ISSN
2041-8213
Volume of the periodical
988
Issue of the periodical within the volume
2
Country of publishing house
US - UNITED STATES
Number of pages
17
Pages from-to
L42
UT code for WoS article
001551898000001
EID of the result in the Scopus database
2-s2.0-105011771388