2003/10/04 by J. K. Cannizzo, N. Gehrels, Ethan T. Vishniac +1 · 2 citations
Physics and Astronomy · #Astro and Planetary Science #Astrophysics #Gamma-ray burst #Gamma-ray bursts and supernovae #Mechanics #Physics #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.1086/380436
published as Astrophys.J. 601 (2004) 380-390 · 30 pages, 10 Postscript figures, uses aasms4.sty
arxiv created 2003/10/04 · openalex publication_date 2004/01/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Utilizing 3D relativistic hydrodynamical calculations, we have examined the evolution of an expanding relativistic blob of gas intended to be representative of a jet associated with ejecta from an extremely energetic event such as a hypernova, that produces a gamma-ray burst (Aloy et al. 2000; Tan, Matzner, & McKee 2001; MacFadyen, Woosley, & Heger 2001, Zhang, Woosley, & Heger 2003, Zhang, Woosley, & MacFadyen 2003). Since these are the first such calculations applied to the blob during the time in which the afterglow radiation is produced, we have purposely kept them simple in an effort to concentrate on the most fundamental aspects of the physics. We restrict our attention to the transition from spherical to jetlike expansion that occurs during the time that the Lorentz factor becomes less than the reciprocal of the jet spreading angle. We have not yet attached specific numbers to our results. From the SRHD equations, one sees that the relevant quantities are the ratios of pressure to density, and of distance to time. If we specify either one of these two sets of numbers, the other one is also determined.