Black Hole Accretion Correlates with Star Formation Rate and Star Formation Efficiency in Nearby Luminous Type 1 Active Galaxies

TL;DR

This study explores the link between black hole growth and star formation in nearby luminous AGNs, revealing that while they are partly driven by shared gas content, there is evidence suggesting AGNs may positively influence star formation efficiency.

Contribution

It provides new insights into the relationship between black hole accretion and star formation, especially highlighting the role of molecular gas and potential positive feedback mechanisms.

Findings

Powerful AGNs have similar gas content as star-forming galaxies.

Star formation rate and black hole accretion rate are weakly correlated after accounting for gas mass.

Positive correlation between star formation efficiency and black hole accretion rate.

Abstract

We investigate the relationship between black hole accretion and star formation in a sample of 453 $z\approx0.3$ type 1 active galactic nuclei (AGNs). We use available CO observations to demonstrate that the combination of nebular dust extinction and metallicity provides reliable estimates of the molecular gas mass even for the host galaxies of type 1 AGNs. Consistent with other similar but significantly smaller samples, we reaffirm the notion that powerful AGNs have comparable gas content as nearby star-forming galaxies and that AGN feedback does not deplete the host of cold gas instantaneously. We demonstrate that while the strong correlation between star formation rate and black hole accretion rate is in part driven by the mutual dependence of these parameters on molecular gas mass, the star formation rate and black hole accretion rate are still weakly correlated after removing the dependence of star formation rate on molecular gas mass. This, together with a positive correlation between star formation efficiency and black hole accretion rate, may be interpreted as evidence for positive AGN feedback.