J/ApJ/807/150ivo://CDS.VizieR/J/ApJ/807/150doi:10.26093/cds/vizier.18070150CDSAkiyama K.Lu R.-S.Fish V.L.Doeleman S.S.Broderick A.E.Dexter J.,Hada K.Kino M.Nagai H.Honma M.Johnson M.D.Algaba J.C.Asada K.,Brinkerink C.Blundell R.Bower G.C.Cappallo R.Crew G.B.Dexter M.,Dzib S.A.Freund R.Friberg P.Gurwell M.Ho P.T.P.Inoue M.,Krichbaum T.P.Loinard L.MacMahon D.Marrone D.P.Moran J.M.,Nakamura M.Nagar N.M.Ortiz-Leon G.Plambeck R.Pradel N.,Primiani R.A.Rogers A.E.E.Roy A.L.Soohoo J.Tavares J.-L.,Tilanus R.P.J.Titus M.Wagner J.Weintroub J.Yamaguchi P.,Young K.H.Zensus A.Ziurys L.M.2017-01-23T22:00:00Z2015-11-20T12:43:08ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleiinterferometryradio-continuum-emissionWe report on 230GHz (1.3mm) very long baseline interferometry (VLBI) observations of M87 with the Event Horizon Telescope using antennas on Mauna Kea in Hawaii, Mt. Graham in Arizona, and Cedar Flat in California. For the first time, we have acquired 230GHz VLBI interferometric phase information on M87 through measurement of the closure phase on the triangle of long baselines. Most of the measured closure phases are consistent with 0{deg} as expected by physically motivated models for 230GHz structure such as jet models and accretion disk models. The brightness temperature of the event-horizon-scale structure is ~1x10^10^K derived from the compact flux density of ~1Jy and the angular size of ~40{mu}as~5.5R_s_, which is broadly consistent with the peak brightness of the radio cores at 1-86GHz located within ~10^2^R_s_. Our observations occurred in the middle of an enhancement in very-high-energy (VHE) {gamma}-ray flux, presumably originating in the vicinity of the central black hole. Our measurements, combined with results of multi-wavelength observations, favor a scenario in which the VHE region has an extended size of ~20-60R_s_.2015ApJ...807..150Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/807/150CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJ/772/13 : VLBI observations of 3C 279 at 230GHz (Lu+, 2013)J/other/Sci/338.355 : 1.3mm VLBI detections of M87 (Doeleman+, 2012)J/ApJ/727/L36 : 1.3mm VLBI observations of Sagittarius A* (Fish+, 2011)J/ApJ/613/279 : ACS Virgo Cluster Survey. III. M87 (Jordan+, 2004)J/ApJS/36/53 : 2380 MHz survey of bright galaxies (Dressel+, 1978)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/807/150https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/807/150http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/807/150https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/807/150https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/807/150http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/807/150GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tap1.5239960011708423e-22 1.5239960011708423e-22RadiodefaultJ/ApJ/807/150/table2Closure phase of M87recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateDate of the observationtime.epochnullableTimeUTC time of the observationtime.epochnullableTriObservational triangle; XYZ (G1)meta.notecharuXYBaseline length of XY baseline in RA direction (G2)instr.baselinedoublevXYBaseline length of XY baseline in Dec direction (G2)instr.baselinedoubleuYZBaseline length of YZ baseline in RA direction (G2)instr.baselinedoublevYZBaseline length of YZ baseline in Dec direction (G2)instr.baselinedoubleuZXBaseline length of ZX baseline in RA direction (G2)instr.baselinefloatvZXBaseline length of ZX baseline in Dec direction (G2)instr.baselinedoublePhaseClosure phasedegtime.phasefloate_PhaseThe 1{sigma} error in Phasedegstat.error;time.phasefloatJ/ApJ/807/150/table3Gain-corrected visibility amplitudes of M87recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateDate of the observationtime.epochnullableTimeUTC time of the observationtime.epochnullableBaselineBaseline (G1)instr.baselinecharuBaseline length in RA direction (G2)instr.baselinedoublevBaseline length in Dec direction (G2)instr.baselinedoubleFlux[0/1.2]? Correlated flux density at 230GHzJyphot.flux.density;em.mm.200-400GHzfloatnullablee_Flux[0/0.2]? The 1{sigma} error in FluxJystat.error;phot.fluxfloatnullable