PoS - Proceedings of Science
Volume 444 - 38th International Cosmic Ray Conference (ICRC2023) - Gamma-ray Astronomy (GA)
Fermi-LAT Detection of a GeV Afterglow from a Compact Stellar Merger
H. Zhang*, Y.Y. Huang, J.H. Zheng, R.Y. Liu and X.Y. Wang
Full text: pdf
Pre-published on: August 17, 2023
Published on:
It is usually thought that the long-duration (>2 s) gamma-ray bursts (GRBs) are associated with massive star core collapse, however the short-duration (<2 s) GRBs are associated with mergers
of compact stellar binaries. In this work, we report the Fermi-LAT detection of gamma-ray
(> 100 MeV) afterglow emission from GRB 211211A, which is a nearby (350 Mpc) long-duration
GRB but discovered as a kilonova association. The gamma-ray emission from GRB 211211A
lasts ∼20,000 s after the burst, which suggests that it is the longest event for conventional short-
duration GRBs ever detected. We suggest that this gamma-ray emission results from afterglow
synchrotron emission. The soft spectrum of GeV emission may arise from a limited maximum
synchrotron energy of only a few hundreds of MeV at ∼20,000 s. The usually long duration of
the GeV emission could be due to the proximity of this GRB and the long deceleration time of
the GRB jet that is expanding in a low-density circumburst medium, consistent with the compact
stellar merger scenario.
DOI: https://doi.org/10.22323/1.444.0887
How to cite

Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in "proceeding" format which is more detailed and complete.

Open Access
Creative Commons LicenseCopyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.