Probable evidence for a transient mega-electron volt emission line in the GRB 221023A.

ABSTRACT: Detection of spectral line in gamma-ray bursts (GRBs) is importance for studying GRB physics, as it provides insights into the composition and physical conditions of the GRB environment. However, progress in detecting X-ray or gamma-ray emission and absorption lines in GRB spectra has been relatively slow, only the narrow emission line feature of about 10 MeV found in GRB 221009A has exhibited a significance exceeding 5σ. Here, we report the probable evidence of a narrow emission feature at about 2.1 mega-electron volts (MeV) in the spectrum of GRB 221023A. The highest statistical significance of this feature is observed in the time interval between 8 and 30 seconds after Fermi Gamma-Ray Burst Monito trigger, with the chance probability value  <2.56 × 10^-5 (after accounting for

SUBMITTER: Jiang LY 

PROVIDER: S-EPMC11920065 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature