J/ApJ/833/88ivo://CDS.VizieR/J/ApJ/833/88doi:10.26093/cds/vizier.18330088CDSLaskar T.Alexander K.D.Berger E.Fong W.-F.Margutti R.Shivvers I.,Williams P.K.G.Kopac D.Kobayashi S.Mundell C.Gomboc A.Zheng W.,Menten K.M.Graham M.L.Filippenko A.V.2023-12-19T09:30:19Z2017-05-03T08:18:06ZCDS support team

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

cds-question@unistra.frgamma-ray-astronomyradio-continuum-emissionWe present the second multi-frequency radio detection of a reverse shock in a {gamma}-ray burst. By combining our extensive radio observations of the Fermi-Large Area Telescope {gamma}-ray burst 160509A at z=1.17 up to 20 days after the burst with Swift X-ray observations and ground-based optical and near-infrared data, we show that the afterglow emission comprises distinct reverse shock and forward shock contributions: the reverse shock emission dominates in the radio band at <~10 days, while the forward shock emission dominates in the X-ray, optical, and near-infrared bands. Through multi-wavelength modeling, we determine a circumburst density of n_0_~10^-3^cm^-3^, supporting our previous suggestion that a low-density circumburst environment is conducive to the production of long-lasting reverse shock radiation in the radio band. We infer the presence of a large excess X-ray absorption column, N_H_~1.5x10^22^cm^-2^, and a high rest-frame optical extinction, A_V_~3.4mag. We identify a jet break in the X-ray light curve at t_jet_~6days, and thus derive a jet opening angle of {theta}_jet_~4{deg}, yielding a beaming-corrected kinetic energy and radiated {gamma}-ray energy of E_K_~4x10^50^erg and E_{gamma}_~1.3x10^51^erg (1-10^4^keV, rest frame), respectively. Consistency arguments connecting the forward shocks and reverse shocks suggest a deceleration time of t_dec_~460s~T_90_, a Lorentz factor of {Gamma}(t_dec_)~330, and a reverse-shock-to-forward-shock fractional magnetic energy density ratio of R_B_={epsilon}_B,RS_/{epsilon}_B,FS_~8. Our study highlights the power of rapid-response radio observations in the study of the properties and dynamics of {gamma}-ray burst ejecta.2016ApJ...833...88Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/833/88CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/MNRAS/397/1177 : Swift-XRT observations of GRBs (Evans+, 2009)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/833/88https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/833/88http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/833/88https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/833/88https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/833/88http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/833/88GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapGamma-rayRadiodefaultJ/ApJ/833/88/table1GRB 160509A: Log of VLA observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDelt[0.3/20] Time since discovery {Delta}t (1)dtime.intervalfloatFreq[1.2/37] Frequency of the observationGHzem.freq;obsfloatFlux[43/2411] Flux density at FrequJyphot.flux.density;em.radiofloate_Flux[11/315] Uncertainty in FluxuJystat.error;phot.fluxfloatDet[0/1]? Detection code for Flux (2)meta.code;instr.saturationintnullableSetupVLA receiver band usedinstr.bandpasschar