Why do galaxies stop forming stars? I. The passive fraction - black hole mass relation for central galaxies

TL;DR

This study shows that the likelihood of a central galaxy being passive strongly correlates with its supermassive black hole mass, supporting the idea that AGN feedback plays a key role in quenching star formation.

Contribution

It demonstrates that black hole mass is the most significant predictor of galaxy passivity, surpassing stellar mass, halo mass, and bulge-to-total ratio, based on a large SDSS galaxy sample.

Findings

Passive fraction strongly depends on black hole mass.

The black hole mass relation remains consistent across different galaxy properties.

Black hole mass is the best predictor of galaxy quenching.

Abstract

We derive the dependence of the fraction of passive central galaxies on the mass of their supermassive black holes for a sample of over 400,000 SDSS galaxies at z < 0.2. Our large sample contains galaxies in a wide range of environments, with stellar masses 8 < log(M*/Msun) < 12, spanning the entire morphological spectrum from pure disks to spheroids. We derive estimates for the black hole masses from measured central velocity dispersions and bulge masses, using a variety of published empirical relationships. We find a very strong dependence of the passive fraction on black hole mass, which is largely unaffected by the details of the black hole mass estimate. Moreover, the passive fraction relationship with black hole mass remains strong and tight even at fixed values of galaxy stellar mass (M*), dark matter halo mass (Mhalo), and bulge-to-total stellar mass ratio (B/T). Whereas, the passive fraction dependence on M*, Mhalo and B/T is weak at fixed MBH. These observations show that, for central galaxies, MBH is the strongest correlator with the passive fraction, consistent with quenching from AGN feedback.