4C 29.30 - extended optical line and radio emission in a probable galaxy merger

Detailed radio and optical observations of the radio galaxy 4C 29.30 are reported which provide clear morphological, polarimetric, kinematical, and energetic evidence for an interaction between the radio source and the ambient medium. The evidence is very strong that the emission-line gas in this galaxy originated from the capture of a gas-rich disk galaxy by the parent galaxy. It is argued that the data strongly support the hypothesis that the emission-line gas associated with radio jets is ambient material, not ejecta from the nucleus. The data also confirm an earlier conclusion that Faraday depolarization of radio continuum emission may be produced by Faraday screens consisting of lumpy gas embedded in, and entrained by, the boundary layers of radio sources. 85 references