Spin Properties of Supermassive Black Holes with Powerful Outflows

TL;DR

This paper investigates the relationship between beam power, disk luminosity, and black hole spin in active galactic nuclei with powerful outflows, proposing a model that links observable properties to black hole spin without assuming a direct correlation with AGN type.

Contribution

It introduces a method to estimate black hole spins from empirical relationships between beam power and disk luminosity, aligning with generalized Blandford-Znajek models.

Findings

Spin and AGN type are not directly related.

The spin function aligns with theoretical models like MAD and ADAF.

A practical example demonstrates spin estimation from outflow data.

Abstract

Relationships between beam power and accretion disk luminosity are studied for a sample of 55 HERG, 13 LERG, and 29 RLQ with powerful outflows. The ratio of beam power to disk luminosity tends to be high for LERG, low for RLQ, and spans the full range of values for HERG. Writing general expressions for the disk luminosity and beam power and applying the empirically determined relationships allows a function that parameterizes the spins of the holes to be estimated. Interestingly, one of the solutions that is consistent with the data has a functional form that is remarkably similar to that expected in the generalized Blandford-Znajek model with a magnetic field that is similar in form to that expected in MAD and ADAF models. Values of the spin function, obtained independent of specific outflow models, suggest that spin and AGN type are not related for these types of sources. The spin function can be used to solve for black hole spin in the context of particular outflow models, and one example is provided.