Multiwavelength Observations of Ring Galaxies. II. Global Star Formation in Ring Galaxies
Abstract
We present optical Hα emission-line images and K band near-infrared images of a sample of collisionally formed ring galaxies. These are used to determine the distribution of star formation and the distribution of the old stellar population, respectively, in the galaxies. Our results show ring galaxies to have similar Hα luminosities to starburst galaxies, with star formation being contained almost exclusively in the ring. In the larger ring galaxies we observe the ionized hydrogen to lie on the outer edge of the underlying, broader, K band ring. No conclusive evidence is found in our sample for a true underlying stellar density wave. Rather, the evidence suggests that either the density waves have passed into the outer, mainly H I disk of the galaxies or that the progenitor galaxies were mainly gas-rich low surface brightness objects and that most of the optical/IR light we now observe has resulted from recent star formation in the expanding ring.
- Publication:
-
The Astronomical Journal
- Pub Date:
- March 1995
- DOI:
- 10.1086/117337
- Bibcode:
- 1995AJ....109.1002M
- Keywords:
-
- Galactic Structure;
- H Alpha Line;
- Infrared Imagery;
- Interacting Galaxies;
- Ring Galaxies;
- Star Distribution;
- Star Formation;
- Star Formation Rate;
- Brightness Distribution;
- Image Analysis;
- Kinematics;
- Luminosity;
- Mass Distribution;
- Stellar Spectrophotometry;
- Astronomy;
- GALAXIES: STELLAR CONTENT;
- GALAXIES: PECULIAR;
- GALAXIES: ABUNDANCES