J/ApJ/821/33ivo://CDS.VizieR/J/ApJ/821/33doi:10.26093/cds/vizier.18210033CDSRunco J.N.Cosens M.Bennert V.N.Scott B.Komossa S.Malkan M.A.,Lazarova M.S.Auger M.W.Treu T.Park D.2018-05-16T06:56:09Z2018-02-20T08:41:42ZCDS support team

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

cds-question@unistra.frseyfert-galaxiesnarrow-band-photometryatomic-spectroscopyredshiftedspectroscopygalaxiesA sample of 102 local (0.02=<z=<0.1) Seyfert galaxies with black hole masses M_BH_>10^7^M_{sun}_ was selected from the Sloan Digital Sky Survey (SDSS) and observed using the Keck 10 m telescope to study the scaling relations between M_BH_ and host galaxy properties. We study profile changes of the broad H{beta} emission line within the three to nine year time frame between the two sets of spectra. The variability of the broad H{beta} emission line is of particular interest, not only because it is used to estimate M_BH_, but also because its strength and width are used to classify Seyfert galaxies into different types. At least some form of broad-line variability (in either width or flux) is observed in the majority (~66%) of the objects, resulting in a Seyfert-type change for ~38% of the objects, likely driven by variable accretion and/or obscuration. The broad H{beta} line virtually disappears in 3/102 (~3%) extreme cases. We discuss potential causes for these changing look active galactic nuclei. While similar dramatic transitions have previously been reported in the literature, either on a case-by-case basis or in larger samples focusing on quasars at higher redshifts, our study provides statistical information on the frequency of H{beta} line variability in a sample of low-redshift Seyfert galaxies.2016ApJ...821...33Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/821/33CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/173 : Catalogue of Seyfert Galaxies (Lipovetsky+, 1988)II/282 : The SDSS Photometric Catalog, Release 6II/294 : The SDSS Photometric Catalog, Release 7V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)J/ApJ/809/20 : The M_BH_-{sigma} relation for active galaxies (Bennert+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/821/33https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/821/33http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/821/33https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/821/33https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/821/33http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/821/33GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/821/33/table23 (Observations, Seyfert-type Classification (table 2) and Results from Spectral Fitting (table 3))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/821/33/table23?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/821/33/table23?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/821/33/table23?GETtext/xml+votable180.050000true3.3974167-9.85580560.0055555555555555566/1 549 4144 4189 4208 4306 4347 4535 4540 4667 4690 4908 4943 5090 5141 5177 5256 5375 5439 5534 5594 5693 5902 5949 5982 6097 6100 6236 6388 6574 6605 6917 7361 8216 8508 8949 9401 9404 9643 9647 9733 9776 10144 10298 10372 10475 10630 10636 10802 10871 10924 10953 10991 10995 11143 11388 11392 12408 17254 17814 17842 18001 18033 18071 18074 18582 18589 18865 19032 19095 19405 19693 19996 21975 23050 23058 23203 25903 26051 26103 26164 26300 26544 27317 27363 27387 27411 27486 27501 27599 27739 27795 27815 28168 28285 28413 28639 28654 31649 32433 32456https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/821/33?format=asciidefaultJ/ApJ/821/33/table23Observations, Seyfert-type Classification (table 2) and Results from Spectral Fitting (table 3)SimbadNameSimbad column added by the CDSmeta.idcharMJDSModified Julian Datedtime.epochintMJDKModified Julian Datedtime.epochinte_FHbpeakS? Uncertainty in FHbpeakSstat.errorfloatnullableFHbpeakS? Peak flux ratio of H{beta} broad/narrow from SDSS spectrumphot.flux;em.line.HbetafloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDTarget identifier (HHMM+DDMM)meta.id;meta.maincharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainzRedshift from SDSS-DR7 (Cat. II/294)src.redshiftfloatDateSDate on which SDSS spectrum was takentime.epochnullableSTypeS[1/1.8] Seyfert-type classification based on SDSS spectrumsrc.classfloatDateKDate on which Keck spectrum was takentime.epochnullableSTypeK[1/1.9] Seyfert-type classification based on Keck spectrum (1)src.classfloatExpTimeExposure time of Keck observation (2)stime.duration;obs.exposureintDTimeTime between SDSS and Keck observationyrtime.intervalfloatDateL? Date on which Lick spectrum was takentime.epochnullableMJDL? Modified Julian Datedtime.epochintnullableSTypeL[1.8/2]? Seyfert-type classification based on Lick spectrumsrc.classfloatnullableSDSSDisplay the online SDSS data for the nearest objectmeta.ref.urlcharn_ID[n] Note on ID (1)meta.notecharsigmaHbS? Second moment of broad H{beta} from SDSS spectrumkm/sstat.varianceintnullablee_sigmaHbS? Uncertainty in sigmaHbSkm/sstat.errorintnullableFWHMS? Full width at half maximum of broad H{beta} from SDSS spectrumkm/sspect.line.widthintnullablee_FWHMS? Uncertainty in FWHMSkm/sstat.errorintnullableFHb/OIIIS? Integrated flux ratio of H{beta}/[O III] from SDSS spectrumphot.flux;em.line.Hbetafloatnullablee_FHb/OIIIS? Uncertainty in FHb/OIIISstat.errorfloatnullableFHbS? Integrated flux ratio of H{beta} broad/narrow from SDSS spectrumphot.flux;em.line.Hbetafloatnullablee_FHbS? Uncertainty in FHbSstat.errorfloatnullableFeIIS[YN] Whether Fe II was subtracted from the SDSS spectrum during the fitting processmeta.codecharsigmaHbK? Second moment of broad H{beta} from Keck spectrumkm/sstat.varianceintnullablee_sigmaHbK? Uncertainty in sigmaHbKkm/sstat.errorintnullableFWHMK? Full width at half maximum of broad H{beta} from Keck spectrumkm/sspect.line.widthintnullablee_FWHMK? Uncertainty in FWHMKkm/sstat.errorintnullableFHb/OIIIK? Integrated flux ratio of H{beta}/[O III] from Keck spectrumphot.flux;em.line.Hbetafloatnullablee_FHb/OIIIK? Uncertainty in FHb/OIIIKstat.errorfloatnullableFHbK? Integrated flux ratio of H{beta} broad/narrow from Keck spectrumphot.flux;em.line.Hbetafloatnullablee_FHbK? Uncertainty in FHbKstat.errorfloatnullableu_FHbK[)] Uncertainty flag on FHbK (2)meta.code.errorcharFHbpeakK? Peak flux ratio of H{beta} broad/narrow from Keck spectrumphot.flux;em.line.Hbetafloatnullablee_FHbpeakK? Uncertainty in FHbpeakKstat.errorfloatnullableu_FHbpeakK[)] Uncertainty flag on FHbpeakK (2)meta.code.errorcharFeIIK[YN] Whether Fe II was subtracted from the Keck spectrum during the fitting processmeta.codechar