J/ApJ/951/93ivo://CDS.VizieR/J/ApJ/951/93doi:10.26093/cds/vizier/ba-xq-2xCDSChen B.-Y.Bower G.C.Dexter J.Markoff S.Ridenour A.Gurwell M.A.,Rao R.Wallstrom S.H.J.2026-07-02T11:59:59Z2025-09-24T09:05:58ZCDS support team

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

cds-question@unistra.frmillimeter-astronomyphotometrysubmillimeter-astronomyactive-galactic-nucleiThe variability of submillimeter emission provides a useful tool to probe the accretion physics in low-luminosity active galactic nuclei. We accumulate four years of observations using the Submillimeter Array for Centaurus A, NGC 4374, NGC 4278, and NGC 5077, and one year of observations for NGC 4552 and NGC 4579. All sources are variable. We measure the characteristic timescale at which the variability is saturated by modeling these sources' light curves as a damped random walk. We detect a timescale for all the sources except NGC 4552. The detected timescales are comparable to the orbital timescale at the event horizon scale for most sources. Combined with previous studies, we show a correlation between the timescale and the black hole mass over 3 orders of magnitude. This discovery suggests the submillimeter emission is optically thin with the emission originating from the event horizon. The mass scaling relationship further suggests that a group of radio sources with a broadband spectrum that peaks at submillimeter wavelengths have similar inner accretion physics. Sources that follow this relationship may be good targets for high- resolution imaging with the Event Horizon Telescope.2023ApJ...951...93Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/951/93CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/698/895 : Variations in QSOs optical flux (Kelly+, 2009)J/ApJS/187/135 : SEDs of weak AGNs associated with LINERs (Eracleous+, 2010)J/ApJ/869/106 : SMARTS & Euler R-band obs. of WFI J2033-4723 (Morgan+, 2018)J/other/Sci/373.789 : optical variability of AGNs (Burke+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/951/93https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/951/93http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/951/93https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/951/93https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/951/93http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/951/93GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/951/93/table1 (Information of full light curve)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/951/93/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/951/93/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/951/93/table1?GETtext/xml+votable180.050000true187.705930812.39112330.0055555555555555566/25647 27765 27773 27914 27936 28495 43262https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/951/93?format=asciiMillimeterdefaultJ/ApJ/951/93/table1Information of full light curverecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameTarget namemeta.id;meta.maincharprimaryMJDSt[52379/57174] Start date, MJDdtime.epochfloatMJDEnd[58484/59789] End date, MJDdtime.epochfloatConsistConsist (#)meta.notecharFlux[0.02/7.8] Mean fluxJyphot.flux.density;em.mm.200-400GHzfloate_Flux[0.005/1.8] Flux uncertaintyJystat.error;phot.flux.density;em.mm.200-400GHzfloatVar[15/84] Mean fraction of variation (1)%stat.fit.goodness;src.varintNfNumber of unpublished flux measurements for this target (link to Table 2)meta.numberintnullableLCInteractive LC Plotmeta.ref.urlcharSimbadNameSimbad column added by the CDSmeta.idcharnullableNEDNED column added by the CDSmeta.ref.urlcharLEDAmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/ApJ/951/93/table2Table of unpublished SMA (the Submillimeter Array) datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource namemeta.id;meta.maincharEpochObservation time'Y:M:D'time.epochnullableFreq[202/264] Observation frequencyGHzem.freq;obsfloatFlux[0.012/9.6] Flux DensityJyphot.flux.density;em.mm.200-400GHzfloate_Flux[0.001/0.4] The 1{sigma} uncertainty in FluxJystat.error;phot.flux.density;em.mm.200-400GHzfloatMaj[0.98/14] Size of beam major axisarcsecphys.angSizefloatMin[0.4/6.2] Size of beam minor axisarcsecphys.angSize;srcfloatPA[-90/90] Position angledegpos.posAngfloat