The Demographics of galactic bulges in the SDSS database
  We present a new database of our two-dimensional bulge-disk decompositions
for 14,233 galaxies drawn from SDSS DR12 in order to examine the properties of
bulges residing in the local universe ($0.005 < z < 0.05$). We performed
decompositions in $g$ and $r$ bands by utilizing the {\sc{galfit}} software.
The bulge colors and bulge-to-total ratios are found to be sensitive to the
details in the decomposition technique, and hence we hereby provide full
details of our method. The $g-r$ colors of bulges derived are almost constantly
red regardless of bulge size except for the bulges in the low bulge-to-total
ratio galaxies ($B/T_{\rm r} \lesssim 0.3$). Bulges exhibit similar scaling
relations to those followed by elliptical galaxies, but the bulges in galaxies
with lower bulge-to-total ratios clearly show a gradually larger departure in
slope from the elliptical galaxy sequence. The scatters around the scaling
relations are also larger for the bulges in galaxies with lower bulge-to-total
ratios. Both the departure in slopes and larger scatters are likely originated
from the presence of young stars. The bulges in galaxies with low
bulge-to-total ratios show signs of a frosting of young stars so substantial
that their luminosity-weighted Balmer-line ages are as small as 1\,Gyr in some
cases. While bulges seem largely similar in optical properties to elliptical
galaxies, they do show clear and systematic departures as a function of
bulge-to-total ratio. The stellar properties and perhaps associated formation
processes of bulges seem much more diverse than those of elliptical galaxies.
