J/ApJ/727/73ivo://CDS.VizieR/J/ApJ/727/73doi:10.26093/cds/vizier.17270073CDSChristensen L.Fynbo J.P.U.Prochaska J.X.Thone C.C.,de Ugarte Postigo A.Jakobsson P.2017-06-28T06:58:07Z2012-09-14T09:07:16ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgamma-ray-astronomyspectroscopyWe present a composite spectrum of 60 long duration gamma-ray burst (GRB) afterglows with redshifts in the range 0.35<z<6.7 observed with low-resolution optical spectra. The composite spectrum covers the wavelength range 700-6600{AA} in the rest frame and has a mean signal-to-noise ratio of 150 per 1{AA} pixel and reaches a maximum of ~300 in the range 2500-3500{AA}. Equivalent widths are measured from metal absorption lines from the Ly{alpha} line to ~5200{AA}, and associated metal and hydrogen lines are identified between the Lyman break and Ly{alpha} line. The average transmission within the Lyman forest is consistent with that found along quasar lines of sight.2011ApJ...727...73Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/727/73CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/530/A21 : Spectral properties of 438 GRBs (Nava+, 2011)J/ApJ/720/1146 : Spectral analysis of GRBs (Lu+, 2010)J/ApJ/701/824 : Afterglows of short and long-duration GRBs (Nysewander+, 2009)J/ApJ/686/1209 : Optical properties of GRB afterglows (Melandri+, 2008)J/ApJS/169/62 : GRB database of spectral lags (Hakkila+, 2007)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/727/73https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/727/73http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/727/73https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/727/73https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/727/73http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/727/73GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapGamma-rayOpticaldefaultJ/ApJ/727/73/table1Weighted composite afterglow spectrumrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[701/6600] Wavelength ({AA})0.1nmem.wlfloatRFluxRelative fluxphot.flux;arith.ratiofloate_RFluxUncertainty in RFluxstat.errordouble