The extraordinarily bright optical afterglow of GRB 991208 and its host galaxy

Simple item page
dc.creatorCastro-Tirado, A. J.
dc.creatorSokolov, V. V.
dc.creatorGorosabel, J.
dc.creatorCerón, J. M. Castro
dc.creatorGreiner, J.
dc.creatorWijers, R. A. M. J.
dc.creatorJensen, B. L.
dc.creatorHjorth, J.
dc.creatorToft, S.
dc.creatorPedersen, H.
dc.creatorPalazzi, E.
dc.creatorPian, E.
dc.creatorMasetti, N.
dc.creatorSagar, R.
dc.creatorMohan, V.
dc.creatorPandey, A. K.
dc.creatorPandey, S. B.
dc.creatorDodonov, S. N.
dc.creatorFatkhullin, T. A.
dc.creatorAfanasiev, V. L.
dc.creatorKomarova, V. N.
dc.creatorMoiseev, A. V.
dc.creatorHudec, R.
dc.creatorSimon, V.
dc.creatorVreeswijk, P.
dc.creatorRol, E.
dc.creatorKlose, S.
dc.creatorStecklum, B.
dc.creatorZapatero-Osorio, M. R.
dc.creatorCaon, N.
dc.creatorBlake, C.
dc.creatorWall, J.
dc.creatorHeinlein, D.
dc.creatorHenden, A.
dc.creatorBenetti, S.
dc.creatorMagazzu, A.
dc.creatorGhinassi, F.
dc.creatorTommasi, L.
dc.creatorBremer, M.
dc.creatorKouveliotou, C.
dc.creatorGuziy, S.
dc.creatorShlyapnikov, A.
dc.creatorHopp, U.
dc.creatorFeulner, G.
dc.creatorDreizler, S.
dc.creatorHartmann, D.
dc.creatorBoehnhardt, H.
dc.creatorParedes, J. M.
dc.creatorMarti, J.
dc.creatorXanthopoulos, E.
dc.creatorKristen, H. E.
dc.creatorSmoker, J.
dc.creatorHurley, H.
dc.date2001-02-09
dc.date2001-02-20
dc.date.accessioned2026-07-07T01:57:40Z
dc.date.available2026-07-07T01:57:40Z
dc.descriptionObservations of the extraordinarily bright optical afterglow (OA) of GRB 991208 started 2.1 d after the event. The flux decay constant of the OA in the R-band is -2.30 +/- 0.07 up to 5 d, which is very likely due to the jet effect, and after that it is followed by a much steeper decay with constant -3.2 +/- 0.2, the fastest one ever seen in a GRB OA. A negative detection in several all-sky films taken simultaneously to the event implies either a previous additional break prior to 2 d after the occurrence of the GRB (as expected from the jet effect). The existence of a second break might indicate a steepening in the electron spectrum or the superposition of two events. Once the afterglow emission vanished, contribution of a bright underlying SN is found, but the light curve is not sufficiently well sampled to rule out a dust echo explanation. Our determination of z = 0.706 indicates that GRB 991208 is at 3.7 Gpc, implying an isotropic energy release of 1.15 x 10E53 erg which may be relaxed by beaming by a factor > 100. Precise astrometry indicates that the GRB coincides within 0.2" with the host galaxy, thus given support to a massive star origin. The absolute magnitude is M_B = -18.2, well below the knee of the galaxy luminosity function and we derive a star-forming rate of 11.5 +/- 7.1 Mo/yr. The quasi-simultaneous broad-band photometric spectral energy distribution of the afterglow is determined 3.5 day after the burst (Dec 12.0) implying a cooling frequency below the optical band, i.e. supporting a jet model with p = -2.30 as the index of the power-law electron distribution.
dc.descriptionAccepted for publication in Astronomy and Astrophysics, 9 pages, 6 figures (Fig. 3 and Fig. 4 have been updated)
dc.identifierhttps://arxiv.org/abs/astro-ph/0102177
dc.identifierhttp://arxiv.org/abs/astro-ph/0102177
dc.identifierAstron.Astrophys. 370 (2001) 398-406
dc.identifierdoi:10.1051/0004-6361:20010247
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/2478
dc.subjectAstrophysics
dc.titleThe extraordinarily bright optical afterglow of GRB 991208 and its host galaxy
dc.typetext

Files

Collections

arXiv