A morphological survey of bar, lens, and ring components in galaxies: secular evolution in galaxy structure.
Abstract
A morphological survey of 121 bright barred spiral galaxies is performed in order to investigate the frequency of incidence, nature, origin, intrinsic shapes, and diameter distributions of bars, lenses, inner rings, outer rings, and global spiral structure. It is found that: (1) lenses and rings are important components in barred galaxies, occurring, respectively, in 54% of SB0-SBa and 76% of SBab and SBc objects; (2) lenses may be manufactured from bars by a process that causes the latter to evolve away into a nearly axisymmetric state; (3) the bar exactly fills the lens in one dimension in at least 17 of 20 galaxies with both a lens and a bar; (4) the stellar content of lenses resembles that of bars; (5) the intrinsic shapes of lenses resemble moderately flattened triaxial ellipsoids, and there may be a causal connection between bars and the triaxial shape of lenses; and (6) the diameters of bars, lenses, and inner and outer rings are well correlated with the total absolute magnitude of the galaxy.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1979
- DOI:
- 10.1086/156782
- Bibcode:
- 1979ApJ...227..714K
- Keywords:
-
- Galactic Evolution;
- Galactic Structure;
- Spiral Galaxies;
- Astronomical Catalogs;
- Bars;
- Lenses;
- Ring Structures;
- Stellar Magnitude;
- Tables (Data);
- Astronomy;
- Barred Spirals:Structure;
- Barred Spirals:Surveys;
- Galaxies:Morphology