2007/09/30 by S. Dado, Shlomo Dado, Arnon Dar +2
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Gamma-ray bursts and supernovae #Physics #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.1086/587952
published as The Astrophysical Journal, 2008, v681, 1408 · Four added figures comparing the evolution of the inferred effective photon spectral index during the fast decline phase of the prompt emission in 14 selected Swift GRBS and the cannonball (CB) model prediction
arxiv created 2008/01/26 · openalex publication_date 2008/07/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Many gamma ray bursts (GRBs) have been observed with the Burst-Alert and X-Ray telescopes of the SWIFT satellite. The successive `pulses' of these GRBs end with a fast decline and a fast spectral softening, until they are overtaken by another pulse, or the last pulse's decline is overtaken by a less rapidly-varying `afterglow'. The fast decline-phase has been attributed, in the standard fireball model of GRBs, to `high-latitude' synchrotron emission from a collision of two conical shells. This interpretation does not agree with the observed spectral softening. The temporal behaviour and the spectral evolution during the fast-decline phase agree with the predictions of the cannonball model of GRBs.