4C 40.36: A Radio Galaxy at a Redshift of 2.3
Abstract
We present long-slit spectroscopy of a faint extended optical object which we have identified with the radio source 4C 40.36. Three emission lines are detected. Their wavelengths match those of C IV λ1549, He II λ1640, and C III] λ1909 to within 0.5% for a redshift of z = 2.269. The extended continuum emission (~20 kpc) together with the large equivalent widths (~100 A) and narrow profiles (~1500 km s^-1^) of the emission lines, all show that 4C 40.36 is a galaxy with properties similar to those of other distant radio galaxies. The redshift of 4C 40.36, however, considerably exceeds that of the most distant radio galaxy (3C 326.1 at z = 1.825) known to date. 4C 40.36 is of additional interest as an excellent example of the recently discovered phenomenon of alignment between the optical and radio axes of powerful distant radio galaxies. The object was investigated as part of our survey of ultra-steep spectrum radio sources, and we show that the selection criteria used to discover 4C 40.36 result in a sample of objects having a relatively low dispersion of monochromatic radio luminosities.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1988
- DOI:
- 10.1086/185137
- Bibcode:
- 1988ApJ...327L..47C
- Keywords:
-
- Cosmology;
- Emission Spectra;
- Line Spectra;
- Radio Galaxies;
- Radio Sources (Astronomy);
- Red Shift;
- Radio Emission;
- Stellar Luminosity;
- Very Large Array (Vla);
- Astrophysics;
- COSMOLOGY;
- GALAXIES: REDSHIFTS;
- RADIO SOURCES: GALAXIES