J/ApJ/779/109ivo://CDS.VizieR/J/ApJ/779/109doi:10.26093/cds/vizier.17790109CDSPeterson B.M.Denney K.D.De Rosa G.Grier C.J.Pogge R.W.Bentz M.C.,Kochanek C.S.Vestergaard M.Kilerci-Eser E.Dalla Bonta E.Ciroi S.2020-04-28T08:16:05Z2015-06-11T13:09:09ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleispectroscopyThe narrow [OIII]{lambda}{lambda}4959,5007 emission-line fluxes in the spectrum of the well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this we show that the narrow-line-emitting region has a radius of only 1-3pc and is denser (n_e_~10^5^/cm3) than previously supposed. The [O III] line width is consistent with virial motions at this radius given previous determinations of the black hole mass. Since the [O III] emission-line flux is usually assumed to be constant and is therefore used to calibrate spectroscopic monitoring data, the variability has ramifications for the long-term secular variations of continuum and emission-line fluxes, though it has no effect on shorter-term reverberation studies. We present corrected optical continuum and broad H{beta} emission-line light curves for the period 1988-2008.2013ApJ...779..109Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/779/109CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/eso : ESO Science Archive Catalog (ESO, 1991-2015)B/hst : HST Archived Exposures Catalog (STScI, 2007)J/ApJS/199/8 : Interstellar column densities compilation (Gudennavar+, 2012)J/ApJ/753/L2 : Reverberation mapping of AGNs (Assef+, 2012)J/ApJ/716/993 : LAMP: reverberation mapping of H and He lines (Bentz+, 2010)J/ApJ/698/895 : Variations in QSOs optical flux (Kelly+, 2009)J/ApJ/613/682 : AGN central masses & broad-line region sizes (Peterson+, 2004)J/A+A/422/925 : Profile variability in lines of NGC 5548 (Shapovalova+ 2004)J/ApJS/143/257 : AGN emission line properties (Kuraszkiewicz+, 2002)J/A+A/371/79 : NGC 5548 UBVRI phot. & Halpha, Hbeta fluxes (Dietrich+, 2001)J/PAZh/27/942 : Nuclear activity of NGC 5548 (Doroshenko+, 2001)J/ApJ/549/155 : [OIII] emission in a sample of AGNs (Nagao+, 2001)J/ApJ/510/659 : Size and Structure of AGN in NGC 5548 (Peterson+, 1999)J/ApJS/112/315 : Spectroscopic parameters of Seyfert nuclei (Ho+ 1997)J/A+A/320/405 : NGC 5548 continuum light curve (Sergeev+ 1997)J/A+A/314/43 : NGC 5548 Profile variability (Kollatschny+ 1996)J/ApJS/98/477 : Optical spectral atlas of Seyfert nuclei (Ho+ 1995)http://www.astronomy.ohio-state.edu/~agnwatch : International AGN Watchhttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/779/109https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/779/109http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/779/109https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/779/109https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/779/109http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/779/109GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapAssociated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/ApJ/779/109defaultJ/ApJ/779/109/table1Unpublished AGN Watch spectroscopic measurementsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateUT date of the observationtime.epoch;obsnullableSpIDName of the spectrum in the International AGN Watch archive (1)meta.id;obscharFOIII[4.4/5.6] Measured observed-frame [OIII]{lambda}5007 flux in 10^-13^erg/s/cm^2^1e-16W.m**-2phot.fluxfloate_FOIII[0.2/0.24] FOIII uncertainty1e-16W.m**-2stat.errorfloatiSpInteractive plot of spectrummeta.ref.urlcharspnon-interactive plot of spectrummeta.ref.urlcharJ/ApJ/779/109/table2[OIII] measurements from recent monitoring campaignsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJDJulian Date of observation; JD-2400000dtime.epochfloatFOIII[3.6/5.3] Observed-frame [OIII]{lambda}5007 emission-line flux in 10^-13^erg/s/cm^2^1e-16W.m**-2phot.fluxfloate_FOIII[0.1/0.4] FOIII uncertainty1e-16W.m**-2stat.errorfloatRef[1/4] Reference for each spectrum (1)meta.ref;pos.frameintJ/ApJ/779/109/table55100{AA} revised continuum light curverecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJDJulian Date of the observation; JD-2400000dtime.epochdoubleF5100Observed-frame AGN flux (1)1e-17W.m**-2.nm**-1phot.fluxfloate_F5100Uncertainty in F51001e-17W.m**-2.nm**-1stat.errorfloatJ/ApJ/779/109/table6Revised H{beta} emission-line light curverecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJDJulian Date of the observation; JD-2400000dtime.epochdoubleFHbObserved-frame H{beta} emission-line flux (1)1e-16W.m**-2phot.fluxfloate_FHbUncertainty in FHb1e-16W.m**-2stat.errorfloat