  We investigated the relationship between supermassive black hole (SMBH) mass
and host starburst luminosity in Seyfert galaxies and Palomar-Green QSOs,
focusing on the host galaxy morphology. Host starburst luminosity was derived
from the 11.3 micron polycyclic aromatic hydrocarbon luminosity. We found that
the SMBH masses of elliptical-dominated host galaxies are more massive than
those of disk-dominated host galaxies statistically. We also found that the
SMBH masses of disk-dominated host galaxies seem to be suppressed even under
increasing starburst luminosity. These findings imply that final SMBH mass is
strongly regulated by host galaxy morphology. This can be understood by
considering the radiation drag model as the SMBH growth mechanism, taking into
account the radiation efficiency of the host galaxy.
