A Revised Calibration of the Virial Mass Estimator for Black Holes in Active Galaxies Based on Single-epoch H$\beta$ Spectra

TL;DR

This paper provides a revised calibration for estimating supermassive black hole masses in active galactic nuclei using single-epoch Hβ spectra, improving accuracy by incorporating recent virial coefficient measurements for different bulge types.

Contribution

It introduces a new calibration of the black hole mass estimator that accounts for recent virial coefficient determinations for pseudo and classical bulges.

Findings

Revised calibration improves black hole mass estimates.

Incorporates recent virial coefficient measurements.

Enhances accuracy for different bulge types.

Abstract

The masses of supermassive black holes in broad-line active galactic nuclei (AGNs) can be measured through reverberation mapping, but this method currently cannot be applied to very large samples or to high-redshift AGNs. As a practical alternative, one can devise empirical scaling relations, based on the correlation between broad-line region size and AGN luminosity and the relation between black hole mass and bulge stellar velocity dispersion, to estimate the virial masses of black holes from single-epoch spectroscopy. We present a revised calibration of the black hole mass estimator for the commonly used H$\beta$ emission line. Our new calibration takes into account the recent determination of the virial coefficient for pseudo and classical bulges.