The Radius-Luminosity Relationship for Active Galactic Nuclei: The Effect of Host-Galaxy Starlight on Luminosity Measurements II. The Full Sample of Reverberation-Mapped AGNs

TL;DR

This study refines the radius-luminosity relationship for active galactic nuclei by accurately accounting for host-galaxy starlight, confirming a power-law slope around 0.52, which supports the idea that AGNs are scaled versions of each other.

Contribution

It provides a comprehensive analysis of host-galaxy starlight effects on luminosity measurements for all reverberation-mapped AGNs, updating the R-L relationship with improved accuracy.

Findings

The power-law slope of the R-L relationship is approximately 0.52.

Host-galaxy starlight significantly affects luminosity measurements.

Results are consistent with previous findings, supporting the scaled AGN model.

Abstract

We present high-resolution HST images of all 35 AGNs with optical reverberation-mapping results, which we have modeled to create a nucleus-free image of each AGN host galaxy. From the nucleus-free images, we determine the host-galaxy contribution to ground-based spectroscopic luminosity measurements at 5100A. After correcting the luminosities of the AGNs for the contribution from starlight, we re-examine the Hbeta R-L relationship. Our best fit for the relationship gives a powerlaw slope of 0.52 with a range of 0.45 - 0.59 allowed by the uncertainties. This is consistent with our previous findings, and thus still consistent with the naive assumption that all AGNs are simply luminosity-scaled versions of each other. We discuss various consistency checks relating to the galaxy modeling and starlight contributions, as well as possible systematic errors in the current set of reverberation measurements from which we determine the form of the R-L relationship.