Empirical Constraints on the Coevolution of Supermassive Black Holes and their Host Spheroids

TL;DR

This study examines the evolution of the black hole mass-velocity dispersion relation by analyzing the scatter in relation to nuclear luminosity, finding that galaxies evolve along this relation regardless of accretion activity.

Contribution

It provides empirical evidence that black holes and their host spheroids coevolve, with the scatter in the MBH-{\sigma} relation being independent of nuclear luminosity.

Findings

Scatter in MBH-{\sigma} relation is uncorrelated with nuclear luminosity.

Galaxies evolve along the MBH-{\sigma} relation at present epoch.

Black holes grow concurrently with their host spheroids.

Abstract

We investigate the evolution of the MBH-{\sigma} relation by examining the relationship between the intrinsic scatter in the MBH-{\sigma} relation and galaxy bolometric nuclear luminosity, the latter being a probe of the accretion rate of the black hole (BH). Our sample is composed of galaxies with classical bulges when possible, of which 38 have dynamically measured BHs masses, and 17 have BHs masses measured by reverberation mapping. In order to obtain the bolometric nuclear luminosity for galaxies with low nuclear luminosity, we convert the X-ray nuclear luminosity measured by Chandra to bolometric luminosity. We find that the scatter in the MBH-{\sigma} relation is uncorrelated with nuclear luminosity over seven orders of magnitude in luminosity, with the high luminosity end approaching the Eddington luminosity. This suggests that at the present epoch galaxies evolve along the MBH-{\sigma} relation. This conclusion is consistent with the standard paradigm that BHs grow contemporaneously with their host stellar spheroids.