J/ApJ/836/186ivo://CDS.VizieR/J/ApJ/836/186doi:10.26093/cds/vizier.18360186CDSJiang Y.-F.Green P.J.Greene J.E.Morganson E.Shen Y.Pancoast A.,Macleod C.L.Anderson S.F.Brandt W.N.Grier C.J.Rix H.-W.Ruan J.J.,Protopapas P.Scott C.Burgett W.S.Hodapp K.W.Huber M.E.Kaiser N.,Kudritzki R.P.Magnier E.A.Metcalfe N.Tonry J.T.Wainscoat R.J.,Waters C.2017-12-13T19:44:22Z2017-11-08T14:34:57ZCDS support team

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

cds-question@unistra.frquasarsinfrared-photometryvisible-astronomybroad-band-photometryredshiftedsurveysWe study the time lags between the continuum emission of quasars at different wavelengths, based on more than four years of multi-band (g, r, i, z) light curves in the Pan-STARRS Medium Deep Fields. As photons from different bands emerge from different radial ranges in the accretion disk, the lags constrain the sizes of the accretion disks. We select 240 quasars with redshifts of z~1 or z~0.3 that are relatively emission-line free. The light curves are sampled from day to month timescales, which makes it possible to detect lags on the scale of the light crossing time of the accretion disks. With the code JAVELIN, we detect typical lags of several days in the rest frame between the g band and the riz bands. The detected lags are ~2-3 times larger than the light crossing time estimated from the standard thin disk model, consistent with the recently measured lag in NGC 5548 and microlensing measurements of quasars. The lags in our sample are found to increase with increasing luminosity. Furthermore, the increase in lags going from g-r to g-i and then to g-z is slower than predicted in the thin disk model, particularly for high-luminosity quasars. The radial temperature profile in the disk must be different from what is assumed. We also find evidence that the lags decrease with increasing line ratios between ultraviolet Fe II lines and Mg II, which may point to changes in the accretion disk structure at higher metallicity.2017ApJ...836..186Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/836/186CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)VII/279 : SDSS quasar catalog: twelfth data release (Paris+, 2017)J/ApJ/613/682 : AGN central masses & broad-line region sizes (Peterson+, 2004)J/ApJ/622/129 : Lag-luminosity relationship in AGN (Sergeev+, 2005)J/ApJ/633/638 : Variable quasar sample from SDSS (Wilhite+, 2005)J/ApJ/698/895 : Variations in QSOs optical flux (Kelly+, 2009)J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)J/A+A/536/A84 : X-ray variability of AGN (Vagnetti+, 2011)J/A+A/542/A83 : CAIXA. II. AGNs from excess variance analysis (Ponti+, 2012)J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)J/ApJS/217/26 : Lick AGN monitoring 2011: light curves (Barth+, 2015)J/ApJ/806/129 : Space telescope RM project. II. Swift data (Edelson+, 2015)J/ApJS/216/4 : SDSS-RM project: technical overview (Shen+, 2015)J/ApJ/821/56 : Space telescope RM project. III. (Fausnaugh+, 2016)J/ApJ/818/30 : Lag measurements for z<0.8 QSOs from the SDSS-RM (Shen+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/836/186https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/836/186http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/836/186https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/836/186https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/836/186http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/836/186GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/836/186/table1 (summary)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/836/186/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/836/186/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/836/186/table1?GETtext/xml+votable180.050000true35.7635-2.95390.0055555555555555565/1629 2856 4422 4423 4758 6814 6/6046 6069 6071 6076 6077 6078 6112 6491 6494 6495 6513 6515 6521 7178 7200 10153 10154 10741 10743 10749 10935 10955 10959 10977 10979 10980 10981 11403 11428 11430 11432 11433 17683 17686 17713 17716 18763 18766 18785 18787 18788 18790 18791 18793 18796 18797 19025 19027 19030 19031 19036 19037 19038 27245 27247 27250 27344 273452.167884311665523e-19 4.670716440110116e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/836/186?format=asciiInfraredOpticaldefaultJ/ApJ/836/186/table1summaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSDSSSDSS identifiermeta.id;meta.maincharprimarycLDDisplay the rest frame lags for the cLD subsample (table3)meta.ref.urlcharRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainz[0.1/1.1] Spectroscopic redshiftsrc.redshiftfloatgmag[15.6/24.1] Pan-STARRS1 apparent g band magnitudemagphot.mag;em.opt.Bfloate_gmag[0/0.5] Uncertainty in gmagmagstat.error;phot.mag;em.opt.Bfloatrmag[15.4/22.2] Pan-STARRS1 apparent r band magnitudemagphot.mag;em.opt.Rfloate_rmag[0/0.2] Uncertainty in rmagmagstat.error;phot.mag;em.opt.Rfloatimag[15.4/22.1] Pan-STARRS1 apparent i band magnitudemagphot.mag;em.opt.Ifloate_imag[0/0.2] Uncertainty in imagmagstat.error;phot.mag;em.opt.Ifloatzmag[15.2/23.4] Pan-STARRS1 apparent z band magnitudemagphot.mag;em.opt.Ifloate_zmag[0.01/0.8] Uncertainty in zmagmagstat.error;phot.mag;em.opt.IfloatlogL[0/47] Log luminosity; erg/slog(1e-07W)phys.luminosityfloatlogMBH[0/10] Log blackhole masslog(solMass)phys.massfloatsigma2Normalized g band excess variancestat.variance;instr.bandpass;arith.ratiocharSloanDisplay the online SDSS data for the nearest objectmeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlcharNEDNED column added by the CDSmeta.ref.urlcharJ/ApJ/836/186/table3Rest frame lags for the sub cLD (quasars with significant detections; see section 4.1)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSDSSSDSS identifier (JHHMMSS.ss+DDMMSS.s)meta.id;meta.mainchardt(g-r)[-1.5/5.6] Rest frame lag {Delta}t_g-r_dtime.intervalfloate_dt(g-r)[0.2/5.3] dt(g-r) uncertaintydstat.errorfloatdt(g-i)[0.8/9.3] Rest frame lag {Delta}t_g-i_dtime.intervalfloate_dt(g-i)[0.2/6.3] dt(g-i) uncertaintydstat.errorfloatdt(g-z)[1.7/14.4] Rest frame lag {Delta}t_g-z_dtime.intervalfloate_dt(g-z)[0.2/3.8] dt(g-z) uncertaintydstat.errorfloat