Models of Extended Radio Sources

Abstract

Some of the basic requirements of viable models of double radio sources are examined. Some models require large mass densities in the most intense radio components and can now be excluded because they predict observable optical emission from the radio components which is not observed. The process of transporting energy from the central object to the radio components is studied, with a view to defining the conditions in which energy can be conveyed without prohibitive losses by adiabatic expansion. It appears likely that energy, and also mass, is brought into the radio components over a time scale comparable with the age of the source. A basic difficulty in accumulating mass in a radio component is outlined.