1997/10/07 by Abhas Mitra · 2 citations
Physics and Astronomy · #Astro and Planetary Science #Astrophysics #Baryon #Blast wave #Confusion #Context (archaeology) #Duration (music) #Gamma-ray burst #Gamma-ray bursts and supernovae #Mechanics #Optics #Physics #Pulsars and Gravitational Waves Research #RADIUS #Radiative transfer #Shock wave #astro-ph
paper · pdf · doi:10.1086/305055
21 pages, LATEX (AAMS4.STY -enclosed), 1 ps. Fig. Accepted in Astrophysical Journal
arxiv created 1997/10/07 · openalex publication_date 1998/01/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Depending upon the various models and assumptions, the existing literature on gamma-ray bursts (GRBs) mentions that the gross theoretical value of the duration of the burst in the hydrodynamical models is τ ~ r γ /2η 2 c , where r γ is the radius at which the blast wave associated with the fireball (FB) becomes radiative and sufficiently strong. Here η ≡ E / Mc 2 , c is the speed of light, E is the initial laboratory frame energy of the FB, and M is the baryonic mass of the same (Rees & Mészáros). However, within the same basic framework, some authors (e.g., Katz and Piran) have given τ ~ r γ /2η c . We intend to remove this confusion by considering this problem at a deeper level than has been considered so far. Our analysis shows that none of the previously quoted expressions are exactly correct, and in case the FB is produced impulsively and the radiative processes responsible for the generation of the GRB are sufficiently fast, its expected duration would be τ ~ ar γ /2η 2 c , where a ~ O (10). We further discuss the probable change, if any, of this expression, in case the FB propagates in an anisotropic fashion. We also discuss some associated points in the context of the Mészáros & Rees scenario.