Properties of galaxies with ring structures
  Aims: We present a statistical analysis of different characteristics of
ringed spiral galaxies with the aim of assessing the effects of rings on disk
galaxy properties. Methods: We built a catalog of ringed galaxies from the
Sloan Digital Sky Survey Data Release 14 (SDSS-DR14). Via visual inspection of
SDSS images, we classified the face-on spiral galaxies brighter than $g < 16.0$
mag into galaxies with: an inner ring, an outer ring, a nuclear ring, both an
inner and an outer ring, and a pseudo-ring. In addition to rings, we recorded
morphological types and the existence of bars, lenses, and galaxy pair
companions with or without interaction. With the goal of providing an
appropriate quantification of the influence of rings on galaxy properties, we
also constructed a suitable control sample of non-ringed galaxies with similar
redshift, magnitude, morphology, and local density environment distributions to
those of ringed ones. Results: We found 1868 ringed galaxies, accounting for
22% of the full sample of spiral galaxies. In addition, within galaxies with
ringed structures, 46% have an inner ring, 10% an outer ring, 20% both an inner
and an outer ring, 6% a nuclear ring, and 18% a partial ring. Moreover, 64% of
the ringed galaxies present bars. We also found that ringed galaxies have both
a lower efficiency of star formation activity and older stellar populations (as
derived with the $D_n(4000)$ spectral index) with respect to non-ringed disk
objects from the control sample. Galaxies with ringed structures present an
excess of high metallicity values compared to non-ringed ones, which show a $12
+ \rm Log (\rm O /\rm H)$ distribution toward lower values. These findings seem
to indicate that rings are peculiar structures that produce an accelerating
galactic evolution, strongly altering the physical properties of their host
galaxies.
