The jet and circumburst stellar wind of GRB 980519

Simple item page
dc.creatorJaunsen, A. O.
dc.creatorHjorth, J.
dc.creatorBjornsson, G.
dc.creatorAndersen, M. I.
dc.creatorPedersen, H.
dc.creatorKjernsmo, K.
dc.creatorKorhonen, H.
dc.creatorSorensen, P. M.
dc.creatorPalazzi, E.
dc.date2000-07-21
dc.date.accessioned2026-07-07T01:54:29Z
dc.date.available2026-07-07T01:54:29Z
dc.descriptionWe present extensive multi-colour (UBVR_CI_C) photometry of the optical afterglow of GRB 980519. Upon discovery, 8.3 hours after the burst, the source was decaying as a power law, (t-t_GRB)^alpha, with a rapid decay rate alpha_1 = - 1.73+-0.04. About 13 hours after the burst a steepening of the light-curve to alpha_2 = -2.22+-0.04 was observed. Within the framework of current afterglow models, we argue that the rapid initial decline, the `break' in the light curve, and the spectral properties of the afterglow are best interpreted as being due to a collimated ultra-relativistic jet of fixed opening angle expanding into an inhomogeneous medium. In this scenario, we find that the circumburst medium has a density structure that goes as r^(-2.05+-0.22). This is characteristic of a preexisting wind expelled from a massive star. A possible physical scenario is that the progenitor star collapsed to form a black hole (i.e., a `collapsar'), producing the observed burst and afterglow. However, the supernova signature expected in the light curve in such a scenario is not detected. This either implies that the redshift of GRB980519 is greater than 1.5 or that supernovae accompanying GRBs are not standard candles.
dc.description11 pages, including 2 tables and 3 figures. Accepted for publication in ApJ, part 1
dc.identifierhttps://arxiv.org/abs/astro-ph/0007320
dc.identifierhttp://arxiv.org/abs/astro-ph/0007320
dc.identifierAstrophys.J. 546 (2001) 127-133
dc.identifierdoi:10.1086/318266
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/1369
dc.subjectAstrophysics
dc.titleThe jet and circumburst stellar wind of GRB 980519
dc.typetext

Files

Collections

arXiv