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