Shaping the relation between the mass of supermassive black holes and the velocity dispersion of galactic bulges

TL;DR

This paper proposes a theoretical model linking supermassive black hole mass to galactic bulge velocity dispersion through radiation heating, aligning well with observational data and explaining their correlated properties.

Contribution

The model offers a new theoretical explanation for the M_BH- ext{} relation based on radiation heating during galaxy formation.

Findings

The model matches empirical M_BH- ext{} relations.

It applies to black holes with masses as low as 10^6 solar masses.

Provides a physical mechanism connecting black hole and bulge properties.

Abstract

I use the fact that the radiation emitted by the accretion disk of supermassive black hole can heat up the surrounding gas in the protogalaxy to achieve hydrostatic equilibrium during the galaxy formation. The correlation between the black hole mass M_BH and velocity dispersion \sigma thus naturally arises. The result generally agrees with empirical fittings from observational data, even with M_BH \leq 10^6M_sun. This model provides a clear picture on how the properties of the galactic supermassive black holes are connected with the kinetic properties of the galactic bulges.