Fermi detection of delayed GeV emission from the short GRB 081024B

TL;DR

This paper reports the first clear detection of extended high-energy emission from a short gamma-ray burst (GRB 081024B) using Fermi, revealing similarities with long GRBs and suggesting new interpretations of their emission mechanisms.

Contribution

It provides the first detailed analysis of extended GeV emission from a short GRB, demonstrating its temporal characteristics and similarities with long GRBs.

Findings

Detection of extended GeV emission lasting about 3 seconds.

Evidence of high-energy emission similarities between short and long GRBs.

First detailed analysis of short GRB extended emission with Fermi.

Abstract

We report on the detailed analysis of the high-energy extended emission from the short Gamma-Ray Burst (GRB) 081024B, detected by the Fermi Gamma-ray Space Telescope. Historically, this represents the first clear detection of temporal extended emission from a short GRB. The light curve observed by the Fermi Gamma-ray Burst Monitor lasts approximately 0.8 seconds whereas the emission in the Fermi Large Area Telescope lasts for about 3 seconds. Evidence of longer lasting high-energy emission associated with long bursts has been already reported by previous experiments. Our observations, together with the earlier reported study of the bright short GRB 090510, indicate similarities in the high-energy emission of short and long GRBs and open the path to new interpretations.