J/A+A/683/A55ivo://CDS.VizieR/J/A+A/683/A55doi:10.26093/cds/vizier.36830055CDSCastro-Tirado A.J.Gupta R.Pandey S.B.Nicuesa Guelbenzu A.,Eikenberry S.Ackley K.Gerarts A.Valeev A.F.Jeong S.Park I.H.,Oates S.R.Zhang B.-B.Sanchez-Ramirez R.Martin-Carrillo A.Tello J.C.,Jelinek M.Hu Y.-D.Cunniffe R.Sokolov V.V.Guziy S.Ferrero P.,Caballero-Garcia M.D.Ror A.K.Aryan A.Castro Tirado M.A.,Fernandez-Garcia E.Gritsevich M.Olivares I.Perez-Garcia I.,Castro Ceron J.M.Cepa J.2024-11-07T20:02:04Z2024-03-04T09:28:27ZCDS support team

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

cds-question@unistra.frgamma-ray-astronomygamma-ray-burstsinfrared-photometryvisible-astronomyDark Gamma-Ray Bursts (GRBs) constitute a significant fraction of the GRB population. In this paper, we present the multiwavelength analysis (both prompt emission and afterglow) of an intense (3.98x10^-5^erg/cm^2^ using Fermi-Gamma-Ray Burst Monitor) two-episodic GRB 150309A observed early on to ~114 days post-burst. Despite the strong gamma-ray emission, no optical afterglow was detected for this burst. However, we discovered near-infrared (NIR) afterglow (KS-band), ~5.2 hours post burst, with the CIRCE instrument mounted at the 10.4m Gran Telescopio Canarias (hereafter GTC). We aim to examine characteristics of GRB 150309A as a dark burst and to constrain other properties using multiwavelength observations. We used Fermi observations of GRB 150309A to understand the prompt emission mechanisms and jet composition. We performed the early optical observations using the BOOTES robotic telescope and late-time afterglow observations using the GTC. A potential faint host galaxy is also detected at optical wavelength using the GTC.We modelled the potential host galaxy of GRB 150309A in order to explore the environment of the burst. The time-resolved spectral analysis of Fermi data indicates a hybrid jet composition consisting of a matter-dominated fireball and magnetic-dominated Poynting flux. GTC observations of the afterglow revealed that the counterpart of GRB 150309A was very red, with H-Ks>2.1mag (95% confidence). The red counterpart was not discovered in any bluer filters of Swift UVOT/BOOTES, indicative of high redshift origin. This possibility was discarded based on multiple arguments, such as spectral analysis of X-ray afterglow constrain z < 4.15 and a moderate redshift value obtained using spectral energy distribution (SED) modelling of the potential galaxy. The broadband (X-ray to NIR bands) afterglow SED implies a very dusty host galaxy with deeply embedded GRB (suggesting AV>~35mag). The environment of GRB 150309A demands a high extinction towards the line of sight, demanding dust obscuration is the most probable origin of optical darkness and the very red afterglow of GRB 150309A. This result makes GRB 150309A the highest extinguished GRB known to date.2024A&A...683A..55Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/683/A55CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/683/A55https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/683/A55http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/683/A55https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/683/A55https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/683/A55http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/683/A55GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/683/A55/list (List of fits images)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/683/A55/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/683/A55/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/683/A55/list?GETtext/xml+votable180.050000true277.0642286.426530.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/683/A556/16367https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/683/A55?format=asciiGamma-rayOpticalInfrareddefaultJ/A+A/683/A55/listList of fits imagesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainscaleScale of the imagearcsec/pixinstr.scalefloatNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintObs.dateObservation datestime.epoch;obsnullablesizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitscharAssocDataAssociated Data web pagemeta.ref.urlchar