Television Photometry of Galaxies in Clusters.
Abstract
An SEC television system was used to obtain optical image data of galaxies in the central regions of six clusters whose redshifts range from 0.05 to 0.20. Typical exposure times were 20 minutes at f/13.5 with wide-band red filters. A method of computer analysis was developed to measure metric and isophotal magnitudes. Approximately 2,900 galaxy images were analyzed with a limiting photometric accuracy of 0.1 magnitudes for a single measurement. Isophotal measurements were taken down to 23 mag/sq. arc sec isophotes, and metric measurements were taken out to 20.3 kpc diameters (H = 50 km/sec Mpc). The relation between mean isophotal surface brightness and isophotal magnitude was considered for each of the six clusters for which galaxy data were obtained. Isophotal and metric magnitudes were compared. Composite luminosity distribution were formed by combining distributions of the six clusters.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- December 1976
- Bibcode:
- 1976PhDT........10H
- Keywords:
-
- Physics: Astronomy and Astrophysics;
- Astronomical Photometry;
- Galactic Clusters;
- Television Systems;
- Computer Techniques;
- Cosmology;
- Isophotes;
- Luminosity;
- Magnitude;
- Red Shift;
- Astronomy