Unleashing Positive Feedback: Linking the Rates of Star Formation, Supermassive Black Hole Accretion and Outflows in Distant Galaxies

TL;DR

This paper explores how pressure from active galactic nuclei influences star formation and black hole growth in distant galaxies, proposing models linking these processes and suggesting observational tests.

Contribution

It introduces a pressure-regulated star formation model incorporating AGN feedback, linking black hole growth, star formation, and outflows in galaxies.

Findings

Pressure-regulated star formation explains the Schmidt-Kennicutt law.

AGN feedback can enhance star formation at high redshift.

Predicted ratios of black hole to spheroid mass vary over time.

Abstract

Pressure-regulated star formation is a simple variant on the usual supernova-regulated star formation efficiency that controls the global star formation rate as a function of cold gas content in star-forming galaxies, and accounts for the Schmidt-Kennicutt law in both nearby and distant galaxies. Inclusion of AGN-induced pressure, by jets and/or winds that flow back onto a gas-rich disk, can lead under some circumstances to significantly enhanced star formation rates, especially at high redshift and most likely followed by the more widely accepted phase of star formation quenching. Simple expressions are derived that relate supermassive black hole growth, star formation and outflow rates. The ratios of black hole to spheroid mass and of both black hole accretion and outflow rates to star formation rate are predicted as a function of time. I suggest various tests of the AGN-triggered star formation hypothesis.