出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We present selected efforts underway to mitigate systematic uncertainties in supermassive black hole (BH) mass estimates. First, we highlight a NLS1-sensitive systematic in determining Balmer-based single-epoch BH masses, where line width measurements may be biased due to contamination from narrow emission-line components. Next, we present recent, detailed reverberation mapping results by showcasing a velocity-delay map of the NLS1 galaxy NGC 4051. This visualization of the transfer function describing the emission line response of the broad line region (BLR) gas to variations in the continuum emission shows the kinematics and geometry of the BLR in velocity and time-domain space. Thesemaps will help to constrain the geometric scale factor, h f i, that is currently the largest source of systematic uncertainty in direct, reverberationbased BH mass measurements. Finally, we show that single-epoch C IV-based BH mass estimates are consistent with their Balmer-based counterparts when efforts are made to use only high S/N data and a homogeneous prescription for line width and luminosity measurements and to correct an observed color dependence in the C IV-to-Balmer mass ratio residuals.
