Relationship of optical emission line gas and extended radio emission in the centers of cooling flow clusters

The radio morphology and the relationship of that morphology to the presence of optical emission-line filaments are discussed for six radio sources associated with central dominant galaxies in the centers of cooling-flow clusters (Abell 2052, Abell 262, Abell 1795, Perseus, Virgo, and 3C295). In some of the sources there appears to be a direct physical connection between the extended radio emission and the optical emission-line gas, whereas in others the emission-line gas seems to share the overall extent and morphology of the radio source but not to be easily associated with specific radio features. Several ways in which the interaction of the radio source with its environment might lead to the formation of optical emission-line filaments are discussed, noting that all of the sources have inversion symmetric radio morphologies. It is suggested that either interaction with a rotating ICM or precession of the central engine may be responsible. 34 references