2019/07/31 by Shen-Shi Du, Da-Bin Lin, Rui-Jing Lu +6
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Cosmic Phenomena #Cutoff #Gamma-ray burst #Gamma-ray bursts and supernovae #Jet (fluid) #Lag #Photon #Radiation #Range (aeronautics) #Shell (structure) #Spectral analysis #Spectral line #astro-ph.HE
paper · pdf · doi:10.3847/1538-4357/ab33fe
15 pages, 20 figures, 1 table, accepted for publication in ApJ
openalex created_date 2019/07/30 · openalex publication_date 2019/09/09 · arxiv created 2019/09/18 · arxiv updated 2019/09/25 · openalex updated_date 2026/08/05
Abstract Recent research shows that the spectral lag is closely related to the spectral evolution in gamma-ray bursts (GRBs). In this paper, we study the spectral lag for a radiating jet shell with a high-energy cutoff radiation spectrum. For the jet shell with a cutoff power-law spectrum, the spectral lag monotonically increases with the photon energy and levels off at a certain photon energy. It is the same for the jet shell with a Band cutoff spectrum (Bandcut). However, a turnover from the positive lags to negative lags appears in the high-energy range for the jet shell with a Bandcut, which is very similar to that observed in GRB 160625B. The dependence of the spectral lags on the spectral shape/evolution is studied in detail. In addition, the spectral lag behavior observed in GRB 160625B is naturally reproduced based on our theoretical outcome.