J/ApJ/884/121ivo://CDS.VizieR/J/ApJ/884/121doi:10.26093/cds/vizier.18840121CDSLaskar T.van Eerten H.Schady P.Mundell C.G.Alexander K.D.,Barniol Duran R.Berger E.Bolmer J.Chornock R.Coppejans D.L.,Fong W.-F.Gomboc A.Jordana-Mitjans N.Kobayashi S.Margutti R.,Menten K.M.Sari R.Yamazaki R.Lipunov V.M.Gorbovskoy E.,Kornilov V.G.Tyurina N.Zimnukhov D.Podesta R.Levato H.,Buckley D.A.H.Tlatov A.Rebolo R.Serra-Ricart M.2021-07-05T11:15:40Z2021-04-19T09:31:28ZCDS support team

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

cds-question@unistra.frgamma-ray-astronomygamma-ray-burstsultraviolet-photometryinfrared-photometryvisible-astronomybroad-band-photometryradio-sourcesWe present comprehensive multiwavelength radio to X-ray observations of GRB 181201A spanning from ~150s to ~163days after the burst, comprising the first joint ALMA-VLA-GMRT observations of a gamma-ray burst (GRB) afterglow. The radio and millimeter-band data reveal a distinct signature at ~3.9days, which we interpret as reverse-shock (RS) emission. Our observations present the first time that a single radio- frequency spectral energy distribution can be decomposed directly into RS and forward shock (FS) components. We perform detailed modeling of the full multiwavelength data set, using Markov Chain Monte Carlo sampling to construct the joint posterior density function of the underlying physical parameters describing the RS and FS synchrotron emission. We uncover and account for all discovered degeneracies in the model parameters. The joint RS-FS modeling reveals a weakly magnetized ({sigma}~3x10^-3^), mildly relativistic RS, from which we derive an initial bulk Lorentz factor of {Gamma}_0_~103 for the GRB jet. Our results support the hypothesis that low-density environments are conducive to the observability of RS emission. We compare our observations to other events with strong RS detections and find a likely observational bias selecting for longer lasting, nonrelativistic RSs. We present and begin to address new challenges in modeling posed by the present generation of comprehensive, multifrequency data sets.2019ApJ...884..121Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/884/121CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJ/781/37 : Multi-band photometry of GRB 130427A (Perley+, 2014)J/ApJ/814/1 : GRB 120326A, 100418A & 100901A multi-wave. obs. (Laskar+, 2015)J/ApJ/833/88 : GRB 160509A VLA monitoring campain results (Laskar+, 2016)J/ApJ/862/94 : Multiwavelength obs. of GRB 161219B (Laskar+, 2018)J/ApJ/858/65 : VLA study of high-redshift GRBs. I. GRB140311A (Laskar+, 2018)J/ApJ/859/134 : VLA study of high-redshift GRBs. II. GRB140304A (Laskar+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/884/121https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/884/121http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/884/121https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/884/121https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/884/121http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/884/121GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapGamma-rayUVOpticalInfraredRadiodefaultJ/ApJ/884/121/table3Radio and millimeter observations of GRB 181201ADet[0/1] Dectection; 1 = yesmeta.codeintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObsObservatory identifier (ALMA, GMRT or VLA)meta.id;instr.obstycharFreq[0.6/97.5] FrequencyGHzem.freqfloatTime[0.88/163.5] Time since burst (2018 December 1 at 02:38 UT)dtime.epochdoubleFlux[0.16/3.42] Flux density from ObsmJyphot.flux.density;em.radiofloate_Flux[0.014/0.6] Uncertainty in FluxmJystat.error;phot.fluxfloatJ/ApJ/884/121/table1Swift UVOT observations of GRB 181201ArecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDelt[0.17/8.76] Mid-time of the observation since burst (2018 December 1 at 02:38 UT)dtime.epochfloatBandSwift/UVOT band usedmeta.code;instr.filtercharFlux[0.0044/0.62] Flux density in BandmJyphot.flux.densitydoublee_Flux[0.001/0.06] Uncertainty in FluxmJystat.error;phot.fluxdoubleDet[0/1] Dectection; 1 = yesmeta.codeintJ/ApJ/884/121/table2Optical and Near-IR observations of GRB 181201ADet[0/1] Dectection; 1 = yesmeta.codeintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDelt[0.0018/23.11] Mid-time of the observation since burst (2018 December 1 at 02:38 UT)dtime.epochdoubleObsObservatory identifiermeta.id;instr.obstycharInstInstrument identifiermeta.id;instrcharFiltFilter usedinstr.setup;instr.filtercharFreq[137000000000000/688000000000000] Frequency of FiltHzem.freqdoubleFlux[0.0067/28.55] Flux density in FiltmJyphot.flux.densitydoublee_Flux[0.00018/0.16] Uncertainty in FluxmJystat.error;phot.fluxdoubleRefReferencemeta.ref;pos.framechar