Lenticular galaxies with UV-rings

TL;DR

This study identifies and analyzes UV rings in lenticular galaxies using GALEX and SDSS data, examining their structure, colors, and possible origins to understand star formation in these galaxies.

Contribution

It provides the first comprehensive analysis of UV rings in lenticular galaxies, combining UV and optical data to explore their structure and origins.

Findings

UV rings are present in a subset of lenticular galaxies.

Optical and UV ring sizes are compared, revealing structural insights.

The origin of outer starforming rings in unbarred galaxies is discussed.

Abstract

By using the public UV imaging data obtained by the GALEX (Galaxy Ultraviolet Explorer) for nearby galaxies, we have compiled a list of lenticular galaxies possessing ultraviolet rings - starforming regions tightly confined to particular radial distances from galactic centers. We have studied large-scale structure of these galaxies in the optical bands by using the data of the SDSS (Sloan Digital Sky Survey): we have decomposed the galactic images into large-scale disks and bulges, have measured the ring optical colours from the residual images after subtracting model disks and bulges, and have compared the sizes of the rings in the optical light and in the UV-band. The probable origin of the outer starforming ring appearances in unbarred galaxies demonstrating otherwise the regular structure and homogeneously old stellar population beyond the rings is discussed.