The extragalactic distance scale. V. Tertiary distance indicators.
Abstract
A sample of 28 nearby galaxies whose distances were previously derived from five primary and four secondary distance indicators is used to calibrate the two main tertiary indicators: the isophotal diameters and the total magnitudes of the galaxies themselves, both fully corrected for galactic and internal extinction as well as redshift. The luminosity class of the DDO system and the morphological type of the revised Hubble system are combined into a composite luminosity index that is more closely correlated with absolute magnitude (or diameter) than either morphological type or luminosity class alone. This luminosity index is corrected for inclination effects and given for the calibrating galaxies, along with corrected isophotal diameters. The total magnitudes are reduced to face-on and corrected for galactic extinction and redshift. The zero points and their mean errors are determined, and the corresponding distance moduli are obtained. An error analysis shows that total magnitudes are better distance indicators than isophotal diameters.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 1979
- DOI:
- 10.1086/156742
- Bibcode:
- 1979ApJ...227..380D
- Keywords:
-
- Astrometry;
- Galactic Clusters;
- Interstellar Extinction;
- Luminous Intensity;
- Astronomical Photometry;
- Calibrating;
- Error Analysis;
- Red Shift;
- Astrophysics;
- Diameters:Galaxies;
- Distance Scale:Universe;
- Distances:Galaxies;
- Galaxies:Luminosities