2003/03/13 by F. Daigne, Frederic Daigne, Daigne, Frederic +3
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Gamma-ray bursts and supernovae #Particle Detector Development and Performance #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0303288
4 pages, 6 figures, to appear in "Gamma-ray bursts in the afterglow era", 3rd workshop, Rome 17-20 Sept. 2002
arxiv created 2003/03/13 · openalex publication_date 2003/03/13 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The prompt emission of gamma-ray bursts (hereafter GRBs) probably comes from a highly relativistic wind which converts its kinetic energy into radiation via the formation of shocks within the wind itself. Such "internal shocks" can occur if the wind is generated with a highly non uniform distribution of the Lorentz factor Gamma. Taking into account such a variable distribution of Gamma, we estimate the expected thermal emission of the relativistic wind when it becomes transparent. We compare this emission (temporal profile + spectrum) to the emission produced by the internal shocks. In most cases we predict a rather bright thermal emission that could easily be detected. This favors acceleration mechanisms for the wind where the main energy reservoir is under magnetic rather than thermal form. Such scenarios can produce thermal X-ray precursors comparable to those observed by GINGA and WATCH/GRANAT.