Axial ratios of edge-on spirals.
Abstract
A diameter-limited sample of 888 normal Sa-Sc galaxies was compiled from the Uppsala General Catalogue. New micrometer measures of the axial ratios A of the disc components of 262 edge-on spirals in this sample were made on copies of blue Palomar Sky Survey plates and calibrated against photometric standards. The distribution of isophotal axial ratios for the whole sample was analysed to give information on the true axial ratios R_0_ of spiral discs. The mean value of log R_0_ is 0.95 +/- 0.03 and the dispersion about this mean is 0.12 +/- 0.04. A similar mean value (0.90) was obtained from a volume-limited subsample of 348 spirals. The dispersion in log R_0_ is partly due to a dependence of R_0_ on morphological type, and the mean value of log R_0_ for each type was estimated. Inclinations of 342 edge-on (R> ~ 3) spirals were determined from their isophotal axial ratios and types. No significant dependence of R_0_ on luminosity at each type was found.
- Publication:
-
Astronomy and Astrophysics Supplement Series
- Pub Date:
- May 1992
- Bibcode:
- 1992A&AS...93..255G
- Keywords:
-
- Astronomical Photometry;
- Galactic Structure;
- Sky Surveys (Astronomy);
- Spiral Galaxies;
- Luminous Intensity;
- Morphology;
- Spectral Line Width;
- Astrophysics