Cold Gas in Massive Galaxies as A Critical Test of Black Hole Feedback Models

Abstract

\n Black hole feedback has been widely implemented as the key recipe to quench star formation in massive galaxies in modern semi-analytic models and hydrodynamical simulations. As the theoretical details surrounding the accretion and feedback of black holes continue to be refined, various feedback models have been implemented across simulations, with notable differences in their outcomes. Yet, most of these simulations have successfully reproduced some observations, such as stellar mass function and star formation rate density in the local Universe. We use the recent observation on the change of neutral hydrogen gas mass (including both H2 and H1) with star formation rate of massive central disc galaxies as a critical test of black hole feedback models across several simulations. We find that IllustrisTNG reproduces the observations significantly better than the other models that we have tested. This favors IllustrisTNG s treatment of active galactic nuclei---where kinetic winds are driven by black holes at low accretion rates---as the most physically plausible amongst those we test. In turn, this also supports the idea that the massive central disc galaxy population in the local Universe was likely quenched by AGN feedback.