摘要：Abstract‘Ringed galaxies’, or disk galaxies with prominent outer ring structures, separated visually from the main galactic bodies, were discovered and intensively studied by B. A. Vorontsov-Vel’yaminov whose 110th anniversary is celebrated this year. We discuss progress reached during recent years in understanding outer ring structures of disk galaxies, in particular, the results of our spectroscopic studies on the ring gas kinematics, excitation and chemical composition.
关键词：Keywordsgalaxies: evolutiongalaxies: structuregalaxies: kinematics and dynamicsgalaxies: elliptical and lenticular
