J/ApJ/806/129ivo://CDS.VizieR/J/ApJ/806/129doi:10.26093/cds/vizier.18060129CDSEdelson R.Gelbord J.M.Horne K.McHardy I.M.Peterson B.M.,Arevalo P.Breeveld A.A.De Rosa G.Evans P.A.Goad M.R.Kriss G.A.,Brandt W.N.Gehrels N.Grupe D.Kennea J.A.Kochanek C.S.Nousek J.A.,Papadakis I.Siegel M.Starkey D.Uttley P.Vaughan S.Young S.,Barth A.J.Bentz M.C.Brewer B.J.Crenshaw D.M.Dalla Bonta E.,De Lorenzo-Caceres A.Denney K.D.Dietrich M.Ely J.Fausnaugh M.M.,Grier C.J.Hall P.B.Kaastra J.Kelly B.C.Korista K.T.Lira P.,Mathur S.Netzer H.Pancoast A.Pei L.Pogge R.W.Schimoia J.S.,Treu T.Vestergaard M.Villforth C.Yan H.Zu Y.2017-07-03T14:25:58Z2015-11-17T15:30:26ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleivisible-astronomybroad-band-photometryultraviolet-astronomyx-ray-sourcesRecent intensive Swift monitoring of the Seyfert 1 galaxy NGC 5548 yielded 282 usable epochs over 125 days across six UV/optical bands and the X-rays. This is the densest extended active galactic nucleus (AGN) UV/optical continuum sampling ever obtained, with a mean sampling rate <0.5 day. Approximately daily Hubble Space Telescope UV sampling was also obtained. The UV/optical light curves show strong correlations (r_max_=0.57-0.90) and the clearest measurement to date of interband lags. These lags are well-fit by a {tau}{propto}{lambda}^4/3^ wavelength dependence, with a normalization that indicates an unexpectedly large disk radius of ~0.35+/-0.05lt-day at 1367{AA}, assuming a simple face-on model. The U band shows a marginally larger lag than expected from the fit and surrounding bands, which could be due to Balmer continuum emission from the broad-line region as suggested by Korista and Goad. The UV/X-ray correlation is weaker (r_max_<0.45) and less consistent over time. This indicates that while Swift is beginning to measure UV/optical lags in general agreement with accretion disk theory (although the derived size is larger than predicted), the relationship with X-ray variability is less well understood. Combining this accretion disk size estimate with those from quasar microlensing studies suggests that AGN disk sizes scale approximately linearly with central black hole mass over a wide range of masses.2015ApJ...806..129Ehttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/806/129CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJ/806/128 : Space telescope RM project. I. NGC5548 (De Rosa+, 2015)J/ApJ/798/95 : HE1104-1805 BVRIJ light curves (Blackburne+, 2015)J/ApJ/779/109 : Long-term monitoring of NGC 5548 (Peterson+, 2013)J/MNRAS/433/1709 : PKS 0558-504 UVOT and XRT monitoring (Gliozzi+, 2013)J/ApJ/753/104 : AGN identifications from AKARI and Swift (Matsuta+, 2012)J/MNRAS/397/1177 : Swift-XRT observations of GRBs (Evans+, 2009)J/ApJ/622/129 : Lag-luminosity relationship in AGN (Sergeev+, 2005)J/ApJ/613/682 : AGN central masses & broad-line reg. sizes (Peterson+, 2004)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/806/129https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/806/129http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/806/129https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/806/129https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/806/129http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/806/129GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalUVX-raydefaultJ/ApJ/806/129/table2Swift/UVOT dataHJDHeliocentric Julian Date (1)dtime.epochdoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFiltSwift/UVOT filter used (UBV, UVM2, UVW1, or UVW2) (1)instr.setup;instr.filtercharFlux[0.5/4.4] Measured flux; in 1e-14erg/s/cm^2^/{AA} unit1e-14cW.m**-2.nm**-1meta.unitfloate_Flux[0.01/0.2] Measured 1{sigma} error in Flux1e-14cW.m**-2.nm**-1stat.error;phot.fluxfloatJ/ApJ/806/129/table3Swift/XRT datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDHeliocentric Julian Date (1)Dtime.epochdoubleHX[0.1/2.2] Measured Swift 0.8-10keV X-ray count ratect/sphot.count;em.X-rayfloate_HX[0.01/0.3] Measured 1{sigma} error in HXct/sstat.errorfloatSX[0.006/0.5] Measured Swift 0.3-0.8keV X-ray count ratect/sphot.count;em.X-rayfloate_SX[0.003/0.2] Measured 1{sigma} error in SXct/sstat.errorfloat