Measuring black hole mass of type I active galactic nuclei by spectropolarimetry

Abstract

Black hole (BH) mass of Type I active galactic nuclei (AGN) can be measured or estimated through either reverberation mapping (RM) or empirical $R-L$ relation, however, both of them suffer from uncertainties of the virial factor ($f_{\mathrm{BLR}}$), thus limiting the measurement accuracy. In this letter, we make an effort to investigate $f_{\mathrm{BLR}}$ through polarised spectra of the broad-line regions (BLR) arisen from electrons in the equatorial plane. Given the BLR composed of discrete clouds with Keplerian velocity around the central BH, we simulate a large number of spectra of total and polarised flux with wide ranges of parameters of the BLR model and equatorial scatters. We find that the $f_{\mathrm{BLR}}$-distribution of polarised spectra is much narrower than that of total ones. This provides a way of n accurately estimating BH mass from single spectropolarimetric observations of type I AGN whose equatorial scatters are identified.

MNRAS Letters (accepted): 5 pages, 3 figures

References in corpus (5)

• Radio-Loudness of Active Galactic Nuclei: Observational Facts and Theoretical Implications
• The Black Hole Mass Scale of Classical and Pseudo Bulges in Active Galaxies
• Modeling reverberation mapping data I: improved geometric and dynamical models and comparison with cross-correlation results
• The spectral energy distribution of PKS 2004-447: a compact steep-spectrum source and possible radio-loud narrow-line Seyfert 1 galaxy
• Polarization in lines - a new method for measuring black hole masses in active galaxies

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