High-Redshift Radio Galaxies from the Molonglo Catalogue
Abstract
We report the results of radio and optical observations of a sample of southern hemisphere radio galaxies selected from the Molonglo Reference Catalogue. The sources were selected to have 408 MHz flux densities greater than 0.9 Jy and low-frequency spectral indices steeper than -0.9. VLA 6 cm maps and optical identifications of 13 sources are presented. All of these sources are identified with faint galaxies, many of which have extended optical structures with morphologies characteristic of high-redshift (z > 0.8) radio galaxies. Long-slit spectroscopic observations have yielded redshifts for 11 of the galaxies, 5 of which are at z > 2. The most distant source in the present sample, 0316 - 257, has a redshift of 3.13, while the median redshift for the sample is 1.6. Our results for this subsample suggest that our total sample of 150 sources may contain ~40 galaxies with z > 2. We have imaged four of our galaxies having z > 2 in the light of Ly α. Three of these have highly extended Ly α emission distributed along their radio axes.
- Publication:
-
The Astronomical Journal
- Pub Date:
- October 1990
- DOI:
- 10.1086/115575
- Bibcode:
- 1990AJ....100.1014M
- Keywords:
-
- Astronomical Catalogs;
- Astronomical Spectroscopy;
- Radio Astronomy;
- Radio Galaxies;
- Red Shift;
- Flux Density;
- Imaging Techniques;
- Southern Hemisphere;
- Astronomy;
- RADIO SOURCES: GALAXIES