Compact steep-spectrum sources from the S4 sample

We present the results of 5-GHz observations with the VLA A-array of a samp le of candidate compact steep-spectrum (CSS) sources selected from the S4 s urvey. We also estimate the symmetry parameters of high-luminosity CSS sour ces selected from different samples of radio sources, and compare these wit h the larger sources of similar luminosity to understand their evolution an d the consistency of the CSS sources with the unified scheme for radio gala xies and quasars. The majority of CSS sources are likely to be young source s advancing outwards through a dense asymmetric environment. The radio prop erties of CSS sources are found to be consistent with the unified scheme, i n which the axes of the quasars are observed close to the line of sight, wh ile radio galaxies are observed close to the plane of the sky.