Automated bar detection in local disc galaxies from the SDSS - The
  colors of bars
  This paper describes an automatic isophotal fitting procedure that succeeds,
without the support of any visual inspection of neither the images nor the
ellipticity/P.A. radial profiles, at extracting a fairly pure sample of barred
LTGs among thousands of optical images from the SDSS. The procedure relies on
the methods described in Consolandi et al. (2016) to robustly extract the
photometrical properties of a large sample of local SDSS galaxies and is
tailored to extract bars on the basis of their well-known peculiarities in
their P.A. and ellipticity profiles. It has been run on a sample of 5853
galaxies in the Coma and Local supercluster. The procedure extracted for each
galaxy a color, an ellipticity and a position angle radial profile of the
ellipses fitted to the isophotes. Examining automatically the profiles of 922
face-on late-type galaxies (B/A >0.7) the procedure found that ~ 36 % are
barred. The local bar fraction strongly increases with stellar mass. The sample
of barred galaxies is used to construct a set of template radial color profiles
in order to test the impact of the barred galaxy population on the average
color profiles shown by Consolandi et al. (2016) and to test the bar-quenching
scenario proposed in Gavazzi et al. (2015). The radial color profile of barred
galaxy shows that bars are on average redder than their surrounding disk
producing an outside-in gradient toward red in correspondence of their
corotation radius. The distribution of the extension of the deprojected length
of the bar suggests that bars have strong impacts on the gradients of averaged
color profiles. The dependence of the profiles on the mass is consistent with
the bar-quenching scenario, i.e. more massive barred galaxies have redder
colors (hence older stellar population and suppressed star formation) inside
their corotation radius with respect to their lower mass counterparts.
