Extragalactic variable radio sources

Radio emission from a plasmoid that expands in a nonspherically symmetric manner is analyzed. The properties of this model are compared with the results of Andrews et al. (1978) and Epstein et al. (1982) concerning the values of beta derived for standard (delayed) radio sources. Mechanisms that might produce plasmoids that expand progressively in length while retaining substantially constant cross-sections are briefly discussed.