J/MNRAS/496/309ivo://CDS.VizieR/J/MNRAS/496/309doi:10.26093/cds/vizier.74960309CDSHoman D.MacLeod C.L.Lawrence A.Ross N.P.Bruce A.2024-08-21T20:15:21Z2023-09-18T14:59:57ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleiblack-holesquasarsredshiftedspectroscopyultraviolet-astronomyvisible-astronomyWe investigate the responsiveness of the 2798{AA} MgII broad emission line in active galactic nuclei (AGNs) on time-scales of several years. Our study is based on a sample of extremely variable AGNs as well as a broad population sample. The observed response of the line in previous studies has been mixed. By focusing on extreme variability (|{Delta}g|>1), we find that MgII clearly does respond to the continuum. However, the degree of responsiveness varies strikingly from one object to another: We see cases of MgII changing by as much as the continuum, more than the continuum, or very little at all. In 74 per cent of the highly variable sample, the behaviour of MgII corresponds with that of H{beta}, with 30 per cent of the objects showing large variations in both lines. We do not detect any change in the line width that would correspond to broad-line region 'breathing', in accordance with results from the literature. Some of the objects in our highly variable sample show a clear asymmetry in the MgII profile. This skewness can be both to the blue and the red of the line centre. Results from our broad population sample show that highly variable quasars have lower Eddington ratios. This result holds for the variability of the continuum, but the correlation is significantly reduced for the variability of the MgII line. For the first time, we present an overview of the value of the intrinsic Baldwin effect for MgII in a large sample.2020MNRAS.496..309Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/496/309CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16)J/ApJ/874/8 : Follow-up spectroscopy of SDSS changing-look QSOshttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/496/309https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/496/309http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/496/309https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/496/309https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/496/309http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/496/309GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/496/309/table4 (Overview of the results of the spectral fitting for the supervariable sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/496/309/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/496/309/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/496/309/table4?GETtext/xml+votable180.050000true2.8060869-11.00654670.0055555555555555566/4792 5071 5817 5953 6424 6536 6543 9191 9400 9471 9785 9870 9952 9990 10016 10252 11346 17248 17254 17515 17763 17772 18021 18075 18096 18782 18788 18838 18850 18856 18865 18881 19050 19200 19413 23043 23189 27231 27285 27945 49014https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/496/309?format=asciiUVOpticaldefaultJ/MNRAS/496/309/table4Overview of the results of the spectral fitting for the supervariable samplezRedshiftsrc.redshiftfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSDSS source designation (HHMMSS.ss+DDMMSS.s)meta.id;meta.maincharMgII[01-] Indicates whether |{Delta}f_MgII_|>=0.5 or the continuum is stable (1)meta.codecharCLQ[0/1] Indicates whether the object was identified as a CLQ in MacLeod et al. (2019ApJ...874....8M, Cat. J/ApJ/874/8)meta.codeintmaxDtspTime span between the spectral epochs, in the AGN rest framedtime.intervalintDL2798Change in the continuum luminosity (2)1e+35Wphys.luminosity;em.UVfloate_DL2798Error on DL2798 (2)1e+35Wstat.errorfloatSimbadSimbad column added by the CDSmeta.ref.urlcharDLMgIIChange in the MgII line luminosity (2)1e+35Wphys.luminosity;em.UVfloate_DLMgIIError on DLMgII (2)1e+35Wstat.errorfloatDf2798Fractional change in the continuum flux level at the line centre (2)phot.flux;arith.ratiofloatDfMgIIFractional change in the MgII line flux (2)phot.flux;arith.ratiofloatDsigmaChange in the MgII line width (2)0.1nmspect.line.eqWidthfloate_DsigmaError on Dsigma (2)0.1nmstat.errorfloatlogLbolLogarithm of the bolometric luminosity (3)log(1e-07W)phys.luminosityfloatlogMBHLogarithm of the black hole mass (3)log(solMass)phys.massfloatlogEddrLogarithm of the Eddington ratio (3)phys.luminosity;arith.ratiofloatmaxDgMaximum absolute change in g-band photometry over the period between spectral observations (4)magphot.mag;arith.difffloatTelTelescope with which the latest spectral observation was madeinstr.tel;obschar_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.main