J/ApJ/727/L36ivo://CDS.VizieR/J/ApJ/727/L36doi:10.26093/cds/vizier.17279036CDSFish V.L.Doeleman S.S.Beaudoin C.Blundell R.Bolin D.E.Bower G.C.,Chamberlin R.Freund R.Friberg P.Gurwell M.A.Honma M.Inoue M.,Krichbaum T.P.Lamb J.Marrone D.P.Moran J.M.Oyama T.Plambeck R.,Primiani R.Rogers A.E.E.Smythe D.L.Soohoo J.Strittmatter P.,Tilanus R.P.J.Titus M.Weintroub J.Wright M.Woody D.Young K.H.,Ziurys L.M.2012-11-10T14:28:31Z2012-10-10T13:12:38ZCDS support team

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

cds-question@unistra.frmillimeter-astronomysubmillimeter-astronomyinterferometrySagittarius A*, the ~4x10^6^M_{sun}_ black hole candidate at the Galactic center, can be studied on Schwarzschild radius scales with (sub)millimeter wavelength very long baseline interferometry (VLBI). We report on 1.3mm wavelength observations of Sgr A* using a VLBI array consisting of the JCMT on Mauna Kea, the Arizona Radio Observatory's Submillimeter Telescope on Mt. Graham in Arizona, and two telescopes of the CARMA array at Cedar Flat in California. Both Sgr A* and the quasar calibrator 1924-292 were observed over three consecutive nights, and both sources were clearly detected on all baselines. For the first time, we are able to extract 1.3mm VLBI interferometer phase information on Sgr A* through measurement of closure phase on the triangle of baselines. On the third night of observing, the correlated flux density of Sgr A* on all VLBI baselines increased relative to the first two nights, providing strong evidence for time-variable change on scales of a few Schwarzschild radii.2011ApJ...727L..36Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/727/L36CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/MNRAS/419/1097 : The EVN Galactic Plane Survey - EGaPS (Petrov, 2012)J/AJ/142/35 : The VLBA Galactic Plane Survey (VGaPS) (Petrov+, 2011)J/ApJ/721/137 : The Bolocam Galactic Plane Survey (BGPS) (Bally+, 2010)J/ApJ/699/186 : VLA observations of the Galactic center (Zhao+, 2009)J/PASJ/52/631 : Galactic plane VERA survey (Honma+, 2000)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/727/L36https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/727/L36http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/727/L36https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/727/L36https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/727/L36http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/727/L36GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapRadiodefaultJ/ApJ/727/L36/table1Gain-corrected detections of 1924-292 and Sgr A*recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource name (1924-292 or Sgr A*)meta.id;meta.maincharObsObservation day of the year (2009-095/2009-097)stime.epoch;obsnullableBaseBaseline designation (JC, JD, SC or SJ)instr.baselinecharBandBand (low [229.089GHz], high [229.601GHz] or both)instr.bandpasscharuThe u visibility in units of M{lambda}obs.paramintvThe v visibility in units of M{lambda}obs.paramintFluxFlux densityJyphot.flux.density;em.mm.200-400GHzfloate_FluxThe 1{sigma} uncertainty in FluxJystat.error;phot.fluxfloat