To study physical and morphological characteristics of distant quasars we carry out radio-optical investigation of 30 quasars from the Cambridge 7C catalogue second area (0.097 square radians). All these objects have angular sizes less than 1 arcsec on 102 MHz images. Average values of absolute magnitudes and spectral indices have been calculated for them (M = −26.51 ± 0.25, a = 0.66±0.25). It was shown that 60% of compact radio sources from the FIRST catalogue (1400 MHz) are candidates of distant quasars.

We present the preliminary analysis of clustering of a sample of 1157 radio-identified galaxies from Machalski & Condon (1999). We found that for separations 2–15 h−1 Mpc their redshift space autocorrelation function ξ(s) can be approximated by the power law with the correlation length ~3.75h−1 Mpc and slope γ ~ 1.8. The correlation length for radiogalaxies is found to be lower and the slope steeper than the corresponding parameters of the control sample of optically observed galaxies. Analysis the projected correlation function Ξ(r) displays possible differences in the clustering properties between active galactic nuclei (AGN) and starburst (SB) galaxies.