The Radius-Luminosity Relationship for Active Galactic Nuclei: The Effect of Host-Galaxy Starlight on Luminosity Measurements

Abstract

We have obtained high resolution images of the central regions of 14 reverberation-mapped active galactic nuclei (AGN) using the Hubble Space Telescope Advanced Camera for Surveys High Resolution Camera to account for host-galaxy starlight contamination of measured AGN luminosities. We measure the host-galaxy starlight contribution to the continuum luminosity at 5100 A through the typical ground-based slit position and geometry used in the reverberation-mapping campaigns. We find that removing the starlight contribution results in a significant correction to the luminosity of each AGN, both for lower luminosity sources, as expected, but also for the higher luminosity sources such as the PG quasars. After accounting for the host galaxy starlight, we revisit the well-known broad-line region radius--luminosity relationship for nearby AGN. We find the power-law slope of the relationship for the H beta line to be 0.518 +/- 0.039, shallower than previously reported and consistent with the slope of 0.5 expected from the naive theoretical assumption that all AGN have, on average, the same ionizing spectrum and the same ionization parameter and gas density in the H beta line-emitting region.

27 pages, 5 tables, 4 figures, accepted to ApJ; full resolution figures available at http://www.astronomy.ohio-state.edu/~bentz/astroph0602412.html

Cited by in corpus (55)

• Biases in Virial Black Hole Masses: An SDSS Perspective
• A New Sample of Low-mass Black Holes in Active Galaxies
• Simultaneous X-ray/optical/UV snapshots of active galactic nuclei from XMM-Newton: spectral energy distributions for the reverberation mapped sample
• The blazar sequence: a new perspective
• The Hard X-ray Spectrum as a Probe for Black-Hole Growth in Radio-Quiet Active Galactic Nuclei
• The effect of radiation pressure on virial black hole mass estimates and the case of Narrow Line Seyfert 1 galaxies
• A Reverberation-Based Mass for the Central Black Hole in NGC 4151
• Broad-line Balmer Decrements in Blue Active Galactic Nuclei
• Cosmic Evolution of Black Holes and Spheroids. III. The M-sigma relation in the last six billion years
• Cosmic Evolution of Mass Accretion Rate and Metalicity in Active Galactic Nuclei
• Black Holes in Pseudobulges and Spheroidals: A Change in the Black Hole-Bulge Scaling Relations at Low Mass
• Cosmic Evolution of Black Holes and Spheroids. II: Scaling Relations at z=0.36
• Black-Hole Mass and Growth Rate at High Redshift
• The Black Hole Mass-Bulge Luminosity Relationship for Active Galactic Nuclei from Reverberation Mapping and Hubble Space Telescope Imaging
• The characteristic blue spectra of accretion disks in quasars as uncovered in the infrared
• On the variability of quasars: a link between Eddington ratio and optical variability?
• The spectrum of the Broad Line Region and the high-energy emission of powerful blazars
• The Mass of the Black Hole in the Seyfert 1 Galaxy NGC 4593 from Reverberation Mapping
• A Revised Broad-Line Region Radius and Black Hole Mass for the Narrow-Line Seyfert 1 NGC 4051
• The UV Continuum of Quasars: Models and SDSS Spectral Slopes
• Multi-wavelength study of the gravitational lens system RXS J1131-1231: III. Long slit spectroscopy: micro-lensing probes the QSO structure
• Host dynamics and origin of Palomar-Green QSOs
• VLT/ISAAC Spectra of the Hbeta Region in Intermediate-Redshift Quasars III. Hbeta Broad Line Profile Analysis and Inferences about BLR Structure
• Observational Constraints on the Dependence of Radio-Quiet Quasar X-ray Emission on Black Hole Mass and Accretion Rate
• The Host Galaxy and Central Engine of the Dwarf AGN POX 52
• Emergence of a Broad-Absorption-Line Outflow in the Narrow-line Seyfert 1 Galaxy WPVS 007
• The Black Hole-Bulge Relationship in Luminous Broad-Line Active Galactic Nuclei and Host Galaxies
• The Origin of the Intrinsic Scatter in the Relation Between Black Hole Mass and Bulge Luminosity for Nearby Active Galaxies
• First Results from the Lick AGN Monitoring Project: The Mass of the Black Hole in Arp 151
• The dependence of quasar variability on black hole mass
• The Black Hole Mass of NGC 4151: Comparison of Reverberation Mapping and Stellar Dynamical Measurements
• X-ray photons from late-decaying majoron dark matter
• Bulk Comptonization spectra in blazars
• Properties of Active Galaxies Deduced from H I Observations
• Intrinsic absorption in 3C 279 at GeV-TeV energies and consequences for estimates of the EBL
• Eddington ratio governs the equivalent width of MgII emission line in active galactic nuclei
• NLS1 galaxies and estimation of their central black hole masses from the X-ray excess variance method
• SDSS J160531.84+174826.1: A Dwarf Disk Galaxy With An Intermediate-Mass Black Hole
• Structure of the Accretion Flow in Broad-Line Radio Galaxies: The Case of 3C390.3
• Low energy cut-offs and hard X-ray spectra in high-z radio-loud quasars: the Suzaku view of RBS315
• MgII Line Variability of High Luminosity Quasars
• Line and continuum variability of two intermediate-redshift, high-luminosity quasars
• Eddington ratios of faint AGN at intermediate redshift: Evidence for a population of half-starved black holes
• Extended emission-line regions in low-redshift quasars: Dependence on nuclear spectral properties
• Constraining the quasar population with the broad-line width distribution
• The Reddest DR3 SDSS/XMM Quasars
• Revisiting the Black Hole Masses of Soft X-ray-Selected Active Galactic Nuclei
• A note on black hole masses estimated by the second moment in Narrow Line Seyfert 1 Galaxies
• The Effect of Variability on the Estimation of Quasar Black Hole Masses
• Active Galactic Nuclei with Double-Peaked Balmer Lines: I. Black Hole Masses and the Eddington ratios
• The optical emission line spectrum of Mark 110
• How many radio-loud quasars can be detected by the Gamma-Ray Large Area Space Telescope?
• A possible bias on the estimate of Lbol/Ledd in AGN as a function of luminosity and redshift
• Spectroscopy of bright quasars: emission lines and internal extinction
• First Detection of 12CO (1--0) Emission from Two Narrow-Line Seyfert 1 Galaxies