2015/03/28 by Romain Hascoët, R. Hascoet, Andrei M. Beloborodov +3
Physics and Astronomy · #Afterglow #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Blast wave #Ejecta #Flare #Gamma-ray burst #Gamma-ray bursts and supernovae #Mechanics #Nuclear physics #Physics #Pulsars and Gravitational Waves Research #Shock (circulatory) #Shock wave #Supernova #X-ray #astro-ph.HE
paper · pdf · doi:10.1093/mnrasl/slx143
5 pages, 3 figures
arxiv created 2015/03/28 · openalex publication_date 2017/09/11 · arxiv updated 2020/02/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract Bright X-ray flares are routinely detected by the Swift satellite during the early afterglow of gamma-ray bursts, when the explosion ejecta drives a blast wave into the external medium. We suggest that the flares are produced as the reverse shock propagates into the tail of the ejecta. The ejecta is expected to contain a few dense shells formed at an earlier stage of the explosion. We show an example of how such dense shells form and describe how the reverse shock interacts with them. A new reflected shock is generated in this interaction, which produces a short-lived X-ray flare. The model provides a natural explanation for the main observed features of the X-ray flares – the fast rise, the steep power-law decline and the characteristic peak duration Δt/t ≃ 0.1–0.3.