J/A+A/618/L10ivo://CDS.VizieR/J/A+A/618/L10doi:10.26093/cds/vizier.36189010CDSGRAVITY CollaborationAbuterR.AmorimA.Bauboeck M.Berger J.P.,Bonnet H.Brandner W.Clenet Y.Coude du Foresto V.de Zeeuw P.T.,Deen C.Dexter J.Duvert G.Eckart A.Eisenhauer F.,Foerster Schreiber N.M.Garcia P.Gao F.Gendron E.Genzel R.,Gillessen S.Guajardo P.Habibi M.Haubois X.Henning T.Hippler S.,Horrobin M.Huber A.Jimenez-Rosales A.Jocou L.Kervella P.,Lacour S.Lapeyrere V.Lazareff B.Le Bouquin J.-B.Lena P.Lippa M.,Ott T.Panduro J.Paumard T.Perraut K.Perrin G.Pfuhl O.Plewa P.M.,Rabien S.Rodriguez-Coira G.Rousset G.Sternberg A.Straub O.,Straubmeier C.Sturm E.Tacconi L.J.Vincent F.von Fellenberg S.,Waisberg I.Widmann F.Wieprecht E.Wiezorrek E.Woillez J.Yazici S.2019-04-18T11:25:35Z2018-11-05T09:34:01ZCDS support team

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

cds-question@unistra.frradio-sourcesastrometryinfrared-sourcesWe report the detection of continuous positional and polarization changes of the compact source SgrA* in high states ('flares') of its variable near- infrared emission with the near-infrared GRAVITY-Very Large Telescope Interferometer (VLTI) beam-combining instrument. In three prominent bright flares, the position centroids exhibit clockwise looped motion on the sky, on scales of typically 150 micro-arcseconds over a few tens of minutes, corresponding to about 30% the speed of light. At the same time, the flares exhibit continuous rotation of the polarization angle, with about the same 45(+/-15)-minute period as that of the centroid motions. Modelling with relativistic ray tracing shows that these findings are all consistent with a near face-on, circular orbit of a compact polarized 'hot spot' of infrared synchrotron emission at approximately six to ten times the gravitational radius of a black hole of 4 million solar masses. This corresponds to the region just outside the innermost, stable, prograde circular orbit (ISCO) of a Schwarzschild-Kerr black hole, or near the retrograde ISCO of a highly spun-up Kerr hole. The polarization signature is consistent with orbital motion in a strong poloidal magnetic field.2018A&A...618L..10Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/618/L10CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/AJ/127/3399 : Sgr A* variability at cm wavelengths (Herrnstein+, 2004)J/MNRAS/428/2731 : Sgr A* emission at 7mm (Beaklini+, 2013)J/ApJ/793/120 : Spitzer/IRAC Sgr A* light curve data (Hora+, 2014)J/ApJ/802/69 : VLA, ALMA and SMA monitoring of Sgr A* (Bower+, 2015)J/MNRAS/454/1525 : XMM-Newton & Chandra monitoring of Sgr A* (Ponti+, 2015)J/other/Sci/348.413 : Sgr A East SNR multiwavelength images (Lau+, 2015)J/ApJ/820/90 : 4yr 1.3mm VLBI observations of SgrA* with EHTJ/A+A/589/A116 : Multiwavelength study of Sgr A* (Mossoux+, 2016)J/A+A/601/A80 : LABOCA 345GHz observations of Sgr A* (Subroweit+, 2017)J/A+A/618/A35 : ALMA images of the CND and Sgr A* (Goicoechea+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/618/L10https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/618/L10http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/618/L10https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/618/L10https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/618/L10http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/618/L10GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfraredRadiodefaultJ/A+A/618/L10/avgJul 22 2018 flare, MJD=58321.9954, flare positions and relative flux, average of Pfuhl+ Waisberg (shown in Fig. 1)xx-offset from SgrA*maspos.eq.ra;arith.diffdoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTimeTime from MJD(0)=58321.9954mintime.epochdoublee_xx-offset uncertaintymasstat.error;pos.cartesian.xdoubleyy-offset from SgrA*maspos.eq.dec;arith.diffdoublee_yy-offset uncertaintymasstat.error;pos.cartesian.ydoubleFluxFlux relative to S2 [15mJy] (1)phot.flux;arith.ratiodoublee_FluxFlux uncertaintystat.error;phot.fluxdoubleJ/A+A/618/L10/waisJul 22 2018 flare, MJD=58321.9954, flare positions and relative flux Waisberg analysis (shown Fig. B1)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTimeTime from MJD(0)=58321.9954mintime.epochdoublexx-offset from SgrA*maspos.eq.ra;arith.diffdoublee_xx-offset uncertaintymasstat.error;pos.cartesian.xdoubleyy-offset from SgrA*maspos.eq.dec;arith.diffdoublee_yy-offset uncertaintymasstat.error;pos.cartesian.ydoubleFluxFlux relative to S2 [15mJy] (1)phot.flux;arith.ratiodoublee_FluxFlux uncertaintystat.error;phot.fluxdoubleJ/A+A/618/L10/pfuhlJul 22 2018 flare, MJD=58321.9954, flare positions and relative flux Pfuhl analysis (shown in Fig. B1)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTimeTime from MJD(0)=58321.9954mintime.epochdoublexx-offset from SgrA*maspos.eq.ra;arith.diffdoublee_xx-offset uncertaintymasstat.error;pos.cartesian.xdoubleyy-offset from SgrA*maspos.eq.dec;arith.diffdoublee_yy-offset uncertaintymasstat.error;pos.cartesian.ydoubleFluxFlux relative to S2 [15mJy] (1)phot.flux;arith.ratiodoublee_FluxFlux uncertaintystat.error;phot.fluxdouble