Globular cluster systems in the Hydra I elliptical galaxies. II.
Abstract
The charactertistics of the globular cluster system Hydra I are investigated through a deep photometric survey around its giant central galaxy, NGC 3311. Measurements of the images obtained indicate that NGC 3311 is surrounded by an extensive and extremely populous cluster system whose approximate projected space density dependence is similar to the light intensity distribution of the galaxy itself. It is noted that NGC 3311 represents the first additional example of a 'supergiant', or anomalously populous, globular cluster system, similar to the system in the Virgo giant elliptical galaxy M87. For any reasonable distance estimate, the cluster specific frequency is greater than about 20, or more than three times the normal value for globular cluster systems in elliptical galaxies generally. The possible connection between the M 87 and NGC 3311 cases is discussed, and it is suggested that their cluster populations were acquired at birth.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1983
- DOI:
- 10.1086/161313
- Bibcode:
- 1983ApJ...272..456H
- Keywords:
-
- Elliptical Galaxies;
- Galactic Clusters;
- Globular Clusters;
- Astronomical Photography;
- Astronomical Photometry;
- Magnitude;
- Radial Distribution;
- Astrophysics