Dependence of Barred Galaxy Fraction on Galaxy Properties and
  Environment
  We investigate the dependence of occurrence of bars in galaxies on galaxy
properties and environment. We use a volume-limited sample of 33,391 galaxies
brighter than $M_{r}=-19.5+5$log$h$ at $0.02\le z\le0.05489$, drawn from the
SDSS DR 7. We classify the galaxies into early and late types, and identify
bars by visual inspection. Among 10,674 late-type galaxies with axis ratio
$b/a>0.60$, we find 3,240 barred galaxies ($f_{bar}=30.4%$) which divide into
2,542 strong bars ($f_{SB1}=23.8%$) and 698 weak bars ($f_{SB2}=6.5%$). We find
that $f_{SB1}$ increases as $u-r$ color becomes redder, and that it has a
maximum value at intermediate velocity dispersion ($\sigma\simeq$150 km
s$^{-1}$). This trend suggests that strong bars are dominantly hosted by
intermediate-mass systems. Weak bars prefer bluer galaxies with lower mass and
lower concentration. In the case of strong bars, their dependence on the
concentration index appears only for massive galaxies with $\sigma>150$ km
s$^{-1}$. We also find that $f_{bar}$ does not directly depend on the
large-scale background density when other physical parameters ($u-r$ color or
$\sigma$) are fixed. We discover that $f_{SB1}$ decreases as the separation to
the nearest neighbor galaxy becomes smaller than 0.1 times the virial radius of
the neighbor regardless of neighbor's morphology. These results imply that
strong bars are likely to be destroyed during strong tidal interactions, and
that the mechanism for this phenomenon is gravitational and not hydrodynamical.
The fraction of weak bars has no correlation with environmental parameters. We
do not find any direct evidence for environmental stimulation of bar formation.
