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 which, with the exception of seven cases, are secure. The redshift distribution N(z) is fairly flat over the redshift range 0 < z < 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-Lyalpha emission line luminosity. 
Steve Rawlings, Steve Eales, Mark Lacy