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dc.contributor.author | Mimica, Petar | |
dc.contributor.author | Giannios, Dimitrios | |
dc.contributor.author | Aloy Toras, Miguel Angel | |
dc.date.accessioned | 2010-08-10T10:56:31Z | |
dc.date.available | 2010-08-10T10:56:31Z | |
dc.date.issued | 2008 | |
dc.identifier.citation | Giannios, D., Mimica, P. and Aloy, M. A. (2008): On the existence of a reverse shock in magnetized gamma-ray burst ejecta, Astronomy and Astrophysics, núm. 478, vol.3, pp. 747-753 | en |
dc.identifier.uri | http://hdl.handle.net/10550/16814 | |
dc.description.abstract | The role of magnetic fields in gamma-ray burst (GRB) flows remains controversial. The study of the early afterglow phases and, in particular, of the reverse shock dynamics and associated emission offers a promising probe of the magnetization of the ejecta. In this paper, we derive the conditions for the existence of a reverse shock in arbitrarily magnetized ejecta that decelerate and interact with the circumburst medium. Both constant and wind-like density profiles are considered. We show, in contrast to previous estimates, that ejecta with magnetization σ0 >∼ 1 are not crossed by a reverse shock for a large fraction of the parameter space relevant to GRB flows. Allowing for shell spreading, there is always a relativistic or mildly relativistic reverse shock forming in σ0 <∼ 0.3 ejecta. From this, we conclude that the paucity of optical flashes, believed to be a distinctive signature of a reverse shock, may be explained by the existence of dynamically important magnetic fields in the ejecta. | en |
dc.language.iso | en | en |
dc.subject | Gamma rays : bursts; Magnetohydrodynamics (MHD); Shock waves | en |
dc.title | On the existence of a reverse shock in magnetized gamma-ray burst ejecta | en |
dc.type | journal article | es_ES |
dc.subject.unesco | UNESCO::ASTRONOMÍA Y ASTROFÍSICA | en |
dc.subject.unesco | UNESCO::ASTRONOMÍA Y ASTROFÍSICA::Otras especialidades astronómicas | en |
dc.identifier.doi | 10.1051/0004-6361:20078931 | en |
dc.identifier.idgrec | 041819 | en |
dc.type.hasVersion | VoR | es_ES |
dc.identifier.url | http://www.aanda.org/index.php?option=com_article&access=doi&doi=10.1051/0004-6361:20078931&Itemid=129 | en |