A sample of 6C radio sources with virtually complete redshifts--II. Optical spectroscopy

This is the second of two papers presenting basic observational data on the 6CE sample of extragalactic radio sources. It presents the results of optical spectroscopy which has yielded virtually complete redshift information for the 6CE sample: 56 of the 59 sample members have spectroscopic redshifts that, with the exception of eight cases, are secure. The redshift distribution N(z) is fairly flat over the redshift range 0z<2, with a median redshift of ≈1.1 and a high-redshift tail reaching to z = 3.4. The highest redshift (z>1.75) members of the 6CE sample have similar optical spectra and a tight (less than one dex) spread in narrow-Lyα emission-line luminosity.