Optical Spectra of a Complete Sample of Radio Sources. I. The Spectra

Abstract

Spectra covering the observed wavelength range 3800 to 9400 A have been obtained for a complete, flux-limited sample of 64 sources that has been studied extensively at radio wavelengths at high angular resolution. The sample is now completely identified—four new finding charts are given, and one source was identified spectroscopically. The spectra were obtained with the 200 inch Hale telescope, primarily with the Double Spectrograph, with spectral resolution of about 9 A at short wavelengths and 18 A at long wavelengths. Redshifts are now known for 62 of the 64 sources; tentative redshifts are given for the remaining two. The redshift range of the sample is 0.0171–2.55. The goal of these observations is a quantitative comparison between the radio structures in these objects, especially the compact nuclei, and the optical spectra. Many of the objects in the sample are faint, and many others have almost featureless spectra. Considerable care was required in the reduction and calibration of the spectra to preserve valuable information on these difficult objects. The spectra are fitted with various components: analytic functions for emission and absorption lines, nonthermal continua, Balmer continua, and thermal continua, and template spectra for starlight and Fe II blends. The signal-to-noise ratio of the spectra, averaged over wavelength, ranges from 2 to 164, with a median of 23. In this paper we describe the observations and data reduction, present the spectra, and give the parameters of components fitted to the spectra.