Contents
- 1. Introduction
- 2. Historical Overview
- 2.1 Inner Ring Structures
- 2.2 Outer Ring Structures
- 2.3 Nuclear Ring Structures
- 3. Comparison of Ring Classifications
- 4. Recent Revisions to the
Classification
- 4.1 Outer Ring and Pseudoring
Morphologies
- 4.2 Inner, Outer, and Nuclear
Lenses
- 5. Confusion of Ring Types in Nonbarred
Galaxies
- 6. Summary of Notation for Ring and Lens
Types
- 7. Rings and Lenses as Distinct Components of
Barred Galaxy Structure
- 8. Rings and Nuclear Activity
- 9. Observations of Galactic Rings
- 9.1 Frequency
- 9.2 Linear and Relative Diameters
- 9.3 Intrinsic Shapes and
Orientations
- 9.4 Photometric Properties
- 9.5 HII Regions in Ringed Galaxies
- 9.6 Neutral Hydrogen Emission from
Ringed Galaxies
- 9.7 CO, IR, and Radio Continuum
Emission from Ringed Galaxies
- 9.8 Kinematic Studies
- 10. Theories of Ring Formation
- 10.1 Some Historical Points
- 10.2 Fundamental Clues from
Observations
- 11. Dynamics of Bars
- 11.1 Bar Formation
- 11.2 Orbits in a Barred Galaxy
- 11.3 Bars in Early- and Late-Type
Galaxies
- 11.4 Pattern Speed Determination
- 11.5 Angular Momentum Transport
- 12. Gas Flows in Barred Galaxies
- 12.1 Hydrodynamics Modeling
- 12.2 Formation of Rings
- 12.3 Role of Viscosity
- 12.4 Fueling the Nucleus
- 13. Self-Gravitating Hydrodynamics
- 13.1 Stability
- 13.2 Self-Gravitating Rings and
Nuclear Spirals
- 14. Problems with Ring Formation
Theory
- 14.1 Time-scales and the
Coexistence of Rings
- 14.2 Bar-Ring Misalignment
- 15. Rings in Nonbarred Galaxies
- 15.1 Bar Destruction, Lens, and Oval
Formation
- 15.2 Evolution Along the Hubble
Sequence
- 16. Interaction Between Several
Waves
- 16.1 Nuclear Bars Inside Nuclear
Rings
- 17. Tidal Interactions and Rings
- 17.1 The Leading Arm Ringed Galaxy NGC
4622
- 17.2 The One-Armed Outer-Ringed Galaxy
NGC 4378
- 17.3 Accretion Rings
- 18. Single-Ringed, Multi-Armed
Galaxies
- 19. Conclusions
- References