Jet Lorentz Factor Constraint for GRB 221009A Based on the Optical Depth of the TeV Photons

Autor: Duan-Yuan Gao, Yuan-Chuan Zou
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: The Astrophysical Journal Letters, Vol 956, Iss 2, p L38 (2023)
Druh dokumentu: article
ISSN: 2041-8213
2041-8205
DOI: 10.3847/2041-8213/acfed1
Popis: The recent detection of teraelectronvolt (TeV) photons from the record-breaking gamma-ray burst GRB 221009A during its prompt phase poses challenges for constraining its Lorentz factor. We reevaluate the constraints on the jet Lorentz factor considering a two-zone model, wherein the TeV photons originate from the external shock region while the lower-energy MeV photons come from the internal prompt emission region. By properly accounting for the evolution of the MeV photon spectrum and light curve, we calculate the optical depth for TeV photons and derive a minimum Lorentz factor of about 300. It is consistent with the afterglow modeling for the TeV emission.
Databáze: Directory of Open Access Journals