Once more on the radio emission of the spiral galaxy nuclei

Correlations between the radio emission of spiral galaxies and the optical evidences of activity of their nuclei are investigated. The centrally located compact radio sources are detected mainly in those galaxies in which split, starlike or semistellar nuclei are observed. It has been also shown that surface brightness of galaxies with relatively large and bright central condensations (marked by 3 in the Byurakan classification) are in the mean greater when central compact radio sources are present. It is suggested that the greater surface brightnesses of galaxies with central radio sources are most probably due to the presence of not very bright stellar nuclei which are invisible on the background of the bright central parts of these galaxies. It is concluded that radio emission of spiral galaxies is caused by active processes in their nuclei