The space density of the Markarian galaxies including a region of the south galactic hemisphere.
Abstract
We present the results of low-dispersion spectroscopic observations of 26 objects in Markarian's fourth list of galaxies with an ultraviolet continuum. This list contains 70 galaxies in an area of the south galactic pole covering some 800 square degrees. Most of the 26 galaxies had already been observed by other workers; however, we report the discovery of two new Seyfert galaxies, Markarian 315 (11 Zw 187) and Markarian 358, which were not recognized earlier. We have used a sample of 242 galaxies in Markarian's lists I-IV to derive estimates for the space densities of these objects as a function of absolute magnitude which are improvements over Sargent's earlier estimates. The results are given in a table. Fainter than Mp = -21 the Markarian galaxies comprise about 10 percent of all galaxies. We present evidence that the low4uminosity Markarian galaxies, those with Mp > -18, are preferentially concentrated in nearby groups and clouds of galaxies. Thus we may have overestimated their space density by using areas of the sky which contain a number of these clouds. Subject headings: galaxies - Seyfert galaxies
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1973
- DOI:
- 10.1086/152510
- Bibcode:
- 1973ApJ...186..433H