Spectroscopy of galaxies in distant clusters. I - First results for 3C 295 and 0024 + 1654
Abstract
ISIT photometry by Butcher and Oemler (1978) has indicated an unusually large fraction of blue galaxies in the distant, concentrated clusters 3C 295 and 0024 + 1654. Low-resolution spectroscopy of 17 galaxies in these fields were obtained in order to ascertain cluster membership and attempt morphological classification of these galaxies by comparing their spectra with those of nearby ellipticals and spirals. Four red galaxies in each field are members of their clusters, and their spectra are consistent with the spectra of present-day ellipticals. The 3C 295 field may be substantially contaminated by field galaxies, whereas 0024 + 1654 does not seem to be. The spectra of the blue galaxies that are known to be, or may be, cluster members are not the spectra of spiral galaxies. Their surface brightnesses also appear too high for normal spiral galaxies. A sizeable fraction (more than 2/7) of the population of blue cluster members have spectra typical of active galactic nuclei, like type 2 Seyferts, which are rare in present-day clusters.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1982
- DOI:
- 10.1086/160524
- Bibcode:
- 1982ApJ...263..533D
- Keywords:
-
- Astronomical Spectroscopy;
- Elliptical Galaxies;
- Galactic Clusters;
- Seyfert Galaxies;
- Spiral Galaxies;
- Active Galactic Nuclei;
- Data Acquisition;
- Data Reduction;
- Spectrum Analysis;
- Astrophysics