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Article Contents
Abstract
Table of 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