J/ApJ/903/112 SDSS Hbeta & C^IV^ reverberation mapped AGNs (Dalla Bonta+, 2020) ================================================================================ The Sloan Digital Sky Survey Reverberation Mapping Project: Estimating Masses of Black Holes in Quasars with Single-epoch Spectroscopy. Dalla Bonta E.D., Peterson B.M., Bentz M.C., Brandt W.N., Ciroi S., De Rosa G., Alvarez G.F., Grier C.J., Hall P.B., Hernandez Santisteban J.V., Ho L.C., Homayouni Y., Horne K., Kochanek C.S., Li J.I.-H., Morelli L., Pizzella A., Pogge R.W., Schneider D.P., Shen Y., Trump J.R., Vestergaard M. =2020ApJ...903..112D ================================================================================ ADC_Keywords: Active gal. nuclei; QSOs; Black holes; Optical; Ultraviolet; Redshifts Keywords: Active galactic nuclei ; Quasars ; Supermassive black holes Abstract: It is well known that reverberation mapping of active galactic nuclei (AGNs) reveals a relationship between AGN luminosity and the size of the broad-line region, and that use of this relationship, combined with the Doppler width of the broad emission line, enables an estimate of the mass of the black hole at the center of the active nucleus based on a single spectrum. An unresolved key issue is the choice of parameter used to characterize the line width, either FWHM or line dispersion {sigma}_line_ (the square root of the second moment of the line profile). We argue here that use of FWHM introduces a bias, stretching the mass scale such that high masses are overestimated and low masses are underestimated. Here we investigate estimation of black hole masses in AGNs based on individual or "single-epoch" observations, with a particular emphasis in comparing mass estimates based on line dispersion and FWHM. We confirm the recent findings that, in addition to luminosity and line width, a third parameter is required to obtain accurate masses, and that parameter seems to be Eddington ratio. We present simplified empirical formulae for estimating black hole masses from the H{beta} {lambda}4861 and C_IV_ {lambda}1549 emission lines. While the AGN continuum luminosity at 5100{AA} is usually used to predict the H{beta} reverberation lag, we show that the luminosity of the H{beta} broad component can be used instead without any loss of precision, thus eliminating the difficulty of accurately accounting for the host-galaxy contribution to the observed luminosity. Description: We use both H{beta} and C^IV^ data from the 2014-2018 SDSS-RM campaign (Grier+, 2017, J/ApJ/851/21 and 2019, J/ApJ/887/38 ; Shen+, 2019, J/ApJS/241/34). File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file tablea3.dat 87 32 Reverberation-mapped AGNs (SDSS H{beta}) tablea4.dat 71 45 Reverberation-mapped AGNs (SDSS C^IV^) -------------------------------------------------------------------------------- See also: J/ApJS/115/185 : 3C 390.3 BVRI and H photometry (Dietrich+, 1998) J/ApJ/510/659 : Size and Structure of AGN in NGC 5548 (Peterson+, 1999) J/A+A/369/57 : Monitoring Mkn279 BVRI & H{beta} fluxes (Santos-Lleo+, 2001) J/ApJ/613/682 : AGN central masses & broad-line region sizes (Peterson+, 2004) J/ApJ/632/799 : NGC4395 light curves (Peterson+, 2005) J/ApJ/667/131 : Mass function of active black holes (Greene+, 2007) J/ApJ/666/757 : CIV 1549{AA} emission line in AGNs (Sulentic+, 2007) J/AJ/135/928 : The black hole-bulge relationship (Shen+, 2008) J/ApJ/680/169 : SDSS DR5 virial black hole masses (Shen+, 2008) J/ApJ/702/1353 : H{beta} and V-band light curves of NGC 4051 (Denney+, 2009) J/ApJ/716/993 : LAMP: reverberation mapping of H and He lines (Bentz+, 2010) J/MNRAS/410/860 : Redshift dependence of BAL QSOs (Allen+, 2011) J/MNRAS/426/416 : Mrk6 H{alpha}, H{beta} & H{gamma} spectra (Doroshenko+, 2012) J/ApJ/755/60 : Reverberation mapping for 5 Seyfert 1 galaxies (Grier+, 2012) J/ApJ/746/169 : Luminosity function of broad-line quasars (Shen+, 2012) J/ApJ/753/125 : Near-IR spectroscopy follow-up 60 SDSS-DR7 QSOs (Shen+, 2012) J/ApJ/779/109 : Long-term monitoring of NGC 5548 (Peterson+, 2013) J/ApJ/782/45 : SEAMBHs. I. Mrk 142, Mrk 335, and IRAS F12397+3333 (Du+, 2014) J/ApJ/795/149 : Reverberation mapping of Seyfert 1 NGC 7469 (Peterson+, 2014) 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/MNRAS/454/3864 : Orientation & QSO black hole mass estimat (Brotherton+ 2015) J/ApJ/806/128 : Space telescope RM project. I. NGC5548 (De Rosa+, 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/804/L15 : SDSS-DR7 broad-line QSOs (Sun+, 2015) J/ApJ/825/126 : SEAMBHs. V. The third year (Du+, 2016) J/ApJ/821/56 : Space telescope RM project III. NGC5548 LCs (Fausnaugh+, 2016) J/ApJ/827/118 : A new reverberation mapping campaign on NGC 5548 (Lu+, 2016) J/ApJ/817/55 : NIR spectroscopy of 1.5