2023/11/23 by Bing Zhang, Zhang, Bing, Xiang‐Yu Wang +3 · 4 citations
Physics and Astronomy · #Gamma-ray bursts and supernovae #Astro and Planetary Science #Astronomy and Astrophysical Research
paper · pdf · doi:10.48550/arxiv.2311.14180
We argue that the broad-band observations of the brightest-of-all-time (BOAT) GRB 221009A reveal a physical picture involving two jet components: a narrow (∼ 0.6 degree half opening angle) pencil-beam jet that has a Poynting-flux-dominated jet composition, and a broader matter-dominated jet with an angular structure. We discuss various observational evidence that supports such a picture. To treat the problem, we develop an analytical structured jet model for both forward and reverse shock emission from the matter dominated structured jet wing during the deceleration phase. We discuss the physical implications of such a two-component jet configuration for this particular burst and for GRBs in general. We argue that some bright X-ray flares could be similar narrow jets viewed slightly outside the narrow jet cone and that narrow jets may exist in many more GRBs without being detected.