The Fundamental Relation between Supermassive Black Holes and Their Host Galaxies

TL;DR

This study confirms key correlations between supermassive black holes and galaxy bulges, introduces a novel fundamental relation linking black hole mass to galaxy properties, and suggests a feedback-driven origin for these correlations.

Contribution

It presents the first analytical combination of black hole masses with the Fundamental Plane, identifying Mbh-sigma_e as the fundamental relation rather than a multi-parameter BH Fundamental Plane.

Findings

Mbh correlates strongly with bulge properties, especially sigma_e.

Pseudobulges do not show significant correlation with SMBHs.

The Mbh-sigma_e relation arises from a transition in AGN feedback mechanisms.

Abstract

We study the correlations between Supermassive Black Holes (BH) and their host galaxies, using a sample of 83 BH masses collected from the most recent and reliable spatially resolved estimates available from the literature. We confirm the mono- and bivariate correlations between SMBHs and the bulges of their host galaxies, confirming that the correlation with the effective velocity dispersion is not significantly improved by higher dimensionality. Instead, pseudobulges do not seem to correlate with their SMBHs, probably because their secular evolution is often unable to trigger accretion onto the central BH. We then present a novel approach aimed at finding the fundamental relation between SMBHs and their host galaxies. For the first time, we analytically combine BH masses with the Fundamental Plane (FP), showing that Mbh-sigma_e appears to be the fundamental relation rather than a putative "BH Fundamental Plane" of the kind Mbh-sigma_e-R_e. These results can be explained by a picture which sees the Mbh-sigma_e relation as a natural outcome of the change in AGN feedback from momentum- to energy-driven. The other scaling relations are then established through the FP.