# On The Role of Supermassive Black Holes in Quenching Star Formation in Local Central Galaxies

## TL;DR

This study investigates how active galactic nucleus (AGN) feedback influences star formation quenching in local central galaxies by comparing semi-analytic models with observational data, revealing model limitations and areas for improvement.

## Contribution

It provides a comparative analysis of two semi-analytic models' AGN feedback schemes against observational data, highlighting their successes and discrepancies in predicting galaxy quenching.

## Key findings

- SAGE model's black hole-bulge relation aligns better with observations.
- Passive fractions correlate with different parameters in models and observations.
- Tensions remain between model predictions and observed galaxy quenching distributions.

## Abstract

In this work, we analyze the role of AGN feedback in quenching star formation for massive, central galaxies in the local Universe. In particular, we compare the prediction of two semi-analytic models (L-GALAXIES and SAGE) featuring different schemes for AGN feedback, with the SDSS DR7 taking advantage of a novel technique for identifying central galaxies in an observational dataset. This enables us to study the correlation between the model passive fractions, which is predicted to be suppressed by feedback from an AGN, and the observed passive fractions in an observationally motivated parameter space. While the passive fractions for observed central galaxies show a good correlation with stellar mass and bulge mass, passive fractions in L-GALAXIES correlate with the halo and black hole mass. For SAGE, the passive fraction correlate with the bulge mass as well. Among the two models, SAGE has a smaller scatter in the black hole - bulge mass (M_BH - M_Bulge) relation and a slope that agrees better with the most recent observations at z \sim 0. Despite the more realistic prescription of radio mode feedback in SAGE, there are still tensions left with the observed passive fractions and the distribution of quenched galaxies. These tensions may be due to the treatment of galaxies living in non-resolved substructures and the resulting higher merger rates that could bring cold gas which is available for star formation.