Effect of bars on the galaxy properties
  Aims: With the aim of assessing the effects of bars on disc galaxy
properties, we present an analysis of different characteristics of spiral
galaxies with strong, weak and without bars. Method: We identified barred
galaxies from the Sloan Digital Sky Survey. By visual inspection, we classified
the face-on spiral galaxies brighter than g<16.5 mag into strong-bar, weak-bar
and unbarred. In order to provide an appropiate quantification of the influence
of bars on galaxy properties, we also constructed a suitable control sample of
unbarred galaxies with similar redshift, magnitude, morphology, bulge sizes,
and local density environment distributions to that of barred galaxies.
Results: We found 522 strong-barred and 770 weak-barred galaxies, representing
a 25.82% of the full sample of spiral galaxies, in good agreement with previous
studies. We also found that strong-barred galaxies show less efficient star
formation activity and older stellar populations compared to weak-barred and
unbarred spirals from the control sample. In addition, there is a significant
excess of strong barred galaxies with red colors. The color-color and
color-magnitude diagrams show that unbarred and weak-barred galaxies are more
extended towards the blue zone, while strong-barred objects are mostly grouped
in the red region. Strong-barred galaxies present an important excess of high
metallicity values, compared to the other types, showing similar 12+log(O/H)
distributions. Regarding the mass-metallicity relation, we found that
weak-barred and unbarred galaxies are fitted by similar curves, while
strong-barred ones show a curve which falls abruptly, with more significance in
the range of low stellar masses (log[Mstar/Msun] < 10.0). These results would
indicate that prominent bars produced an accelerating effect on the gas
processing, reflected in the significant changes in the physical properties of
their host.
