Polarization in Lines—a New Method for Measuring Black Hole Masses in Active Galaxies

Measuring 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 the evolution of galaxies. Here, we present a new method for measuring SMBH masses using the polarization of the broad lines emitted from active galactic nuclei (AGNs). We performed spectropolarometric observations of nine AGNs and found that this method gives measured masses that 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.