Radio emission of isolated single and double galaxies

A comparison of the radio luminosities of isolated single and double galaxies has shown that spiral galaxies which are members of pairs have a radio luminosity which exceeds that of single galaxies by 2.5 times on the average. The power of the radio emission of members of pairs depends on the projection onto the celestial sphere of the linear distance between the components of the pairs. For example, members of pairs with projection of the distance between them less than 10 kpc have a radio luminosity greater by 2-2.5 times than members of pairs for which the distance between them is greater than 50 kpc. Members of interacting pairs are more powerful emitters in the radio range. It is also shown that spiral galaxies that are members of triplets have radio luminosities that are apparently not interior to members of pairs.