SDSS-IV MaNGA: The link between bars and the early cessation of star
  formation in spiral galaxies
  Bars are common in low-redshift disk galaxies, and hence quantifying their
influence on their host is of importance to the field of galaxy evolution. We
determine the stellar populations and star formation histories of 245 barred
galaxies from the MaNGA galaxy survey, and compare them to a mass- and
morphology-matched comparison sample of unbarred galaxies. At fixed stellar
mass and morphology, barred galaxies are optically redder than their unbarred
counterparts. From stellar population analysis using the full spectral fitting
code Starlight, we attribute this difference to both older and more metal-rich
stellar populations. Dust attenuation however, is lower in the barred sample.
The star formation histories of barred galaxies peak earlier than their
non-barred counterparts, and the galaxies build up their mass at earlier times.
We can detect no significant differences in the local environment of barred and
un-barred galaxies in this sample, but find that the HI gas mass fraction is
significantly lower in high-mass ($\rm{M}_{\star} > 10^{10}~\rm{M}_{\odot}$)
barred galaxies than their non-barred counterparts. We speculate on the
mechanisms that have allowed barred galaxies to be older, more metal-rich and
more gas-poor today, including the efficient redistribution of galactic
fountain byproducts, and a runaway bar formation scenario in gas-poor disks.
While it is not possible to fully determine the effect of the bar on galaxy
quenching, we conclude that the presence of a bar and the early cessation of
star formation within a galaxy are intimately linked.
