The First Supermassive Black Hole Mass Measurement in Active Galactic Nuclei Using the Polarization of Broad Emission Line Mg ii

Spectropolarimetric efforts in the last few years have developed an efficient method that is based on the profiles of the polarization plane position angle of broad emission lines in active galactic nuclei. Here we present black hole measurements of SBS 1419+538 using spectropolarimetric observations in the Mg ii spectral band. The observations are performed by the 6 m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS) using SCORPIO-2. We found good agreement for this object's estimated supermassive black hole mass using spectropolarimetry compared with the mass obtained using other methods.