Star formation activity of barred spiral galaxies
  We study the star formation activity of nearby galaxies with bars using a
sample of late-type galaxies at 0.02$\leq z \leq$ 0.05489 and $M_r <-19.5$ from
the Sloan Digital Sky Survey. We compare the physical properties of strongly
and weakly barred galaxies with those of non-barred galaxies that have stellar
mass and redshift distributions similar to barred galaxies. We find that the
star formation activity of strongly barred galaxies probed by starburstiness,
$\it{g-r}$, NUV$-r$, and mid-infrared [3.4]$-$[12] colors is, on average, lower
than that of non-barred galaxies. However, weakly barred galaxies do not show
such a difference between barred and non-barred galaxies. The amounts of atomic
and molecular gas in strongly barred galaxies are smaller than those of
non-barred galaxies, and the gas metallicity is higher in strongly barred
galaxies than in non-barred galaxies. The gas properties of weakly barred
galaxies again show no difference from those of non-barred galaxies. We stack
the optical spectra of barred and non-barred galaxies in several mass bins and
fit to the stacked spectra with a spectral fitting code, STARLIGHT. We find no
significant difference in stellar populations between barred and non-barred
galaxies for both strongly and weakly barred galaxies. Our results are
consistent with the idea that the star formation activity of barred galaxies is
enhanced in the past along with significant gas consumption, and is currently
lower than or similar to that of non-barred galaxies. The past star formation
enhancement depends on the strength of bars.
