The first supermassive black hole mass measurement in active galactic nuclei using the polarization of broad emission line Mg II

TL;DR

This paper demonstrates a novel spectropolarimetric method to measure the mass of a supermassive black hole in an active galactic nucleus using the polarization of the Mg II emission line, confirming its effectiveness.

Contribution

It introduces the first SMBH mass measurement in an AGN via polarization of the Mg II broad emission line, expanding spectropolarimetric techniques.

Findings

Good agreement with previous SMBH mass estimates

Validates spectropolarimetry as a reliable method for SMBH mass measurement

First application of Mg II polarization in SMBH studies

Abstract

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