GRB 200826A: A Precursor of a Long Gamma-Ray Burst with Missing Main Emission

Ivy Wang, Xiangyu and Zhang, Bin-Bin and Lei, Wei-Hua (2022) GRB 200826A: A Precursor of a Long Gamma-Ray Burst with Missing Main Emission. The Astrophysical Journal Letters, 931 (1). L2. ISSN 2041-8205

[thumbnail of Ivy_Wang_2022_ApJL_931_L2.pdf] Text
Ivy_Wang_2022_ApJL_931_L2.pdf - Published Version

Download (728kB)

Abstract

The recently discovered peculiar gamma-ray burst GRB 200826A poses a dilemma for the collapsar model. Although all other characteristics of the burst are consistent with it being a Type II (i.e., collapse of a massive star) event, the observed duration of the event is only approximately 1 s, which is at odds with the predicted allowable timescale range for a collapsar event. To resolve this dilemma, this Letter proposes that the original burst could be an intrinsically long GRB comprising a precursor and a main emission phase. However, the main emission phase is missed due to either precession of the jet or the obstruction by a companion star, leaving only the precursor observed as a short-duration GRB 200826A. Interestingly, we found that the temporal and spectral properties of GRB 200826A broadly resembled those of the bright precursor observed in GRB 160625B. Furthermore, assuming the prototype burst of GRB 200826A is similar to that of GRB 160625B, we found that the observer may indeed miss its main emission because of geometric effects caused either by jet precession or companion-obstruction models. Our approach provides a natural explanation for the GRB 200826A–like bursts and agrees with the rarity of those events.

Item Type: Article
Subjects: Research Asian Plos > Physics and Astronomy
Depositing User: Unnamed user with email support@research.asianplos.com
Date Deposited: 27 Apr 2023 07:50
Last Modified: 30 Oct 2024 07:19
URI: http://abstract.stmdigitallibrary.com/id/eprint/651

Actions (login required)

View Item
View Item