One-zone models for spheroidal galaxies with a central supermassive black-hole. Self-regulated Bondi accretion

TL;DR

This study uses a one-zone model with self-regulated Bondi accretion to simulate the co-evolution of supermassive black holes and galaxies, capturing key phases like obscured star formation and quiescent states.

Contribution

It introduces a novel one-zone model incorporating self-regulated Bondi accretion to reproduce galaxy and black hole co-evolution phases.

Findings

Models reproduce obscured-cold and hot quiescent phases.

A Compton-thick phase is common during the cold phase.

Best fit to Magorrian relation occurs with low-mass seeds and efficiency ~0.1.

Abstract

By means of a one-zone evolutionary model, we study the co-evolution of supermassive black holes and their host galaxies, as a function of the accretion radiative efficiency, dark matter content, and cosmological infall of gas. In particular, the radiation feedback is computed by using the self-regulated Bondi accretion. The models are characterized by strong oscillations when the galaxy is in the AGN state with a high accretion luminosity. We found that these one-zone models are able to reproduce two important phases of galaxy evolution, namely an obscured-cold phase when the bulk of star formation and black hole accretion occur, and the following quiescent hot phase in which accretion remains highly sub-Eddington. A Compton-thick phase is also found in almost all models, associated with the cold phase. An exploration of the parameter space reveals that the closest agreement with the present-day Magorrian relation is obtained, independently of the dark matter halo mass, for galaxies with a low-mass seed black hole, and the accretion radiative efficiency ~0.1.