Measuring of the masses of galactic supermassive black holes (SMBHs) is an important task, since they correlate with the host galaxy properties and play an important role in evolution of galaxies. Here we present a new method for measuring of SMBH ma
sses using the polarization of the broad lines emitted from active galactic nuclei (AGNs). We performed spectropolarometric observations of 9 AGNs and find that this method gives measured masses which are in a good agreement with reverberation measurements. An advantage of this method is that it can be used to measure the masses of SMBHs in a consistent way at different cosmological epochs.
Here we present the spectropolarimetric observations of the radio loud active galaxy 3C 390.3 in the period 2009-2014 (24 epochs). The galaxy has been observed with the 6-meter telescope of SAO RAS using the SCORPIO spectropolarimeter. We explore the
variability and lags in the polarized light of the continuum and broad H$alpha$ line. We give the Stokes parameters $Q, U$, degree of linear polarization $P$ and the position angle of the polarization plane, $varphi$, for 24 epochs. We find a small lag~(10-40 days) between the unpolarized and polarized continuum that is significantly smaller than the estimated lags for the unpolarized broad emission lines (lag(H$alpha$)$sim$138-186 and lag(H$beta$)$sim$60-79 days). This shows that the region of the variable polarized continuum is significantly smaller than the broad line region, indicating that a part of the polarized continuum is coming from the jet. The lag of the polarized light in the H$alpha$ line (89-156 days) indicates an additional component to the disc one that has an outflowing velocity of $sim$-1200 km s$^{-1}$. This region seems to depolarize the polarized broad H$alpha$ line emitted from the disc and scattered in the inner part of the torus.
