Revealing ringed galaxies in group environments

Aims. We explore galaxies with ringed structures inhabiting poor and richgroups with the aim of assessing the effects of local density environments onringed galaxy properties. Methods. We identified galaxies with inner, outer,nuclear, inner+outer (inner and outer rings combined), and partial rings thatreside in groups by cross-correlating a sample of ringed galaxies with a groupcatalog obtained from Sloan Digital Sky Survey (SDSS). The resulting sample wasdivided based on group richness. To quantify the effects of rings and the roleof local density environment on galaxy properties, we constructed a suitablecontrol sample for each catalog of ringed galaxies, consisting of non-ringedgalaxies with similar values for the z, magnitude, morphology, group masses,and environmental density distributions as those of ringed ones. We exploredthe occurrence of ringed galaxies in poor and rich groups and analyzed severalgalaxy properties, such as SFR, stellar populations, and colors. Results. Weobtained a sample of 637 ringed galaxies residing in groups. With 76% of thesegalaxies inhabiting poor groups and 24% rich groups. In addition, ringedgalaxies in groups display a reduction in their star formation activity andaged stellar populations, compared to non-ringed ones in the control samples.However, the SFR is higher for nuclear rings in poor groups than for othertypes. This disparity may stem from the environmental influence on the internalprocesses of galaxies, either enhancing or diminishing star formation. Ringedgalaxies also show an excess of red colors and tend to populate the greenvalley and the red sequence of color-magnitude and color-color diagrams, with asurplus of galaxies in the red sequence, while non-ringed galaxies are found inthe green valley and the blue region. These trends are more significant ingalaxies with ringed structures residing in rich groups.