Constraints on Spin of a Supermassive Black Hole in Quasars with Big Blue Bump

TL;DR

This study estimates the spin of supermassive black holes in quasars using spectral energy distributions and polarimetric data, revealing most are high-spin Kerr black holes, which impacts understanding of AGN accretion processes.

Contribution

It introduces a method combining spectral energy distribution analysis and polarimetric observations to estimate SMBH spins in AGNs, providing new insights into their accretion efficiency.

Findings

Most SMBHs in the sample are high-spin Kerr black holes.

The radiation efficiency correlates with SMBH spin.

Polarimetric data are crucial for accurate inclination angle determination.

Abstract

We determined the spin value of supermassive black hole (SMBH) in active galactic nuclei (AGN) with investigated ultraviolet-to-optical spectral energy distribution, presented in the sample of Shang et al. (2005). The estimates of the spin values have been produced at the base of the standard geometrically thin accretion disk model and with using the results of the polarimetric observations. The polarimetric observations are very important for determining the inclination angle of AGN disk. We presented the results of our determinations of the radiation efficiency of the accretion flow and values of the spins of SMBHs, that derives the coefficient of radiation efficiency. The majority of SMBHs of AGNs from Shang et al. (2005) sample are to be the Kerr black holes with the high spin value.