Reverberation Mapping of Two Luminous Quasars: the Broad-line Region Structure and Black Hole Mass

Abstract

We report the results of a multi-year spectroscopic and photometric monitoring campaign of two luminous quasars, PG~0923+201 and PG~1001+291, both located at the high-luminosity end of the broad-line region (BLR) size-luminosity relation with optical luminosities above $10^{45}\mathrm{erg}{\mathrm{s}}^{-1}$. PG~0923+201 is for the first time monitored, and PG~1001+291 was previously monitored but our campaign has a much longer temporal baseline. We detect time lags of variations of the broad H$\beta$, H$\gamma$, Fe {\sc ii} lines with respect to those of the 5100~Å continuum. The velocity-resolved delay map of H$\beta$ in PG~0923+201 indicates a complicated structure with a mix of Keplerian disk-like motion and outflow, and the map of H$\beta$ in PG~1001+291 shows a signature of Keplerian disk-like motion. Assuming a virial factor of $f_{\mathrm{BLR}}=1$ and FWHM line widths, we measure the black hole mass to be $118_{-16}^{+11}\times 10^7{M}_{\odot }$ for PG~0923+201 and $3.33_{-0.54}^{+0.62}\times 10^7{M}_{\odot }$ for PG~1001+291. Their respective accretion rates are estimated to be $0.21_{-0.07}^{+0.06}\times L_{\mathrm{Edd}}{c}^{-2}$ and $679_{-227}^{+259}\times L_{\mathrm{Edd}}{c}^{-2}$, indicating that PG~0923+201 is a sub-Eddington accretor and PG~1001+291 is a super-Eddington accretor. While the H$\beta$ time lag of PG~0923+201 agrees with the size-luminosity relation, the time lag of PG~1001+291 shows a significant deviation, confirming that in high-luminosity AGN the BLR size depends on both luminosity and Eddington ratio. Black hole mass estimates from single AGN spectra will be over-estimated at high luminosities and redshifts if this effect is not taken into account.

21 pages, 14 figures, accepted

References in corpus (24)

• The Zwicky Transient Facility: System Overview, Performance, and First Results
• A Catalog of Quasar Properties from SDSS DR7
• The Zwicky Transient Facility: Data Processing, Products, and Archive
• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• The Zwicky Transient Facility: Science Objectives
• The diversity of quasars unified by accretion and orientation
• Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. IV. H$\beta$ Time Lags and Implications for Super-Eddington Accretion
• The Lick AGN Monitoring Project 2011: Spectroscopic Campaign and Emission-Line Light Curves
• The Radius-Luminosity Relationship Depends on Optical Spectra in Active Galactic Nuclei
• The Black Hole Mass Scale of Classical and Pseudo Bulges in Active Galaxies
• Space Telescope and Optical Reverberation Mapping Project. V. Optical Spectroscopic Campaign and Emission-Line Analysis for NGC 5548
• The effect of nuclear gas distribution on the mass determination of supermassive black holes
• Self-shadowing Effects of Slim Accretion Disks in Active Galactic Nuclei: Diverse Appearance of the Broad-line Region
• Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. III. Detection of Fe II Reverberation in Nine Narrow-Line Seyfert 1 Galaxies
• Highly Accreting Quasars: Sample Definition and Possible Cosmological Implications
• First Results from the Lick AGN Monitoring Project: The Mass of the Black Hole in Arp 151
• A Bayesian Method for the Intercalibration of Spectra in Reverberation Mapping
• Calibration of the virial factor $f$ in supermassive black hole masses of reverberation-mapped AGNs
• Reverberation mapping of narrow-line Seyfert 1 galaxy I Zwicky 1: black hole mass
• Reverberation Mapping of Changing-look Active Galactic Nucleus NGC 3516
• A Non-parametric Approach to Constrain the Transfer Function in Reverberation Mapping
• A New Approach to Constrain Black Hole Spins in Active Galaxies Using Optical Reverberation Mapping
• Broad-line Region of the Quasar PG 2130+099 from a Two-Year Reverberation Mapping Campaign with High Cadence
• Active Galactic Nuclei with Ultra-fast Outflows Monitoring Project: The Broad-line Region of Mrk 79 as a Disk Wind