GRB 221009A: Observations with LST-1 of CTAO and implications for structured jets in Long Gamma-Ray Bursts

Kód výsledku v 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>

Nalezeny alternativní kódy

RIV/68378271:_____/25:00644401 RIV/00216208:11320/25:10510660 RIV/61989592:15310/25:73633192

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

GRB 221009A: Observations with LST-1 of CTAO and implications for structured jets in Long Gamma-Ray Bursts

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

GRB 221009A: Observations with LST-1 of CTAO and implications for structured jets in Long Gamma-Ray Bursts

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Astrophysical Journal Letters

ISSN

2041-8205

e-ISSN

2041-8213

Svazek periodika

988

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

17

Strana od-do

L42

Kód UT WoS článku

001551898000001

EID výsledku v databázi Scopus

2-s2.0-105011771388