Cluster-subcluster mergers and the formation of narrow-angle tailed radio sources

We examine the ROSAT PSPC X‐ray properties of a sample of 15 Abell clusters containing 23 narrow‐angle tailed (NAT) radio galaxies. We find that clusters with NATs show a significantly higher level of substructure than a similar sample of radio‐quiet clusters, indicating that NAT radio sources are preferentially located in dynamically complex systems. Also, the velocity distribution of the NAT galaxies is similar to that of other cluster members; these velocities are inadequate for producing the ram pressure necessary to bend the radio jets. We therefore propose a new model for NAT formation, in which NATs are associated with dynamically complex clusters undergoing merger events. The U‐shaped NAT morphology is produced in part by the merger‐induced bulk motion of the ICM bending the jets.