Are narrow-angle radio tails always bent by hot gasquestionMark

Radio galaxies take a variety of morphology. One particularly interesting classis the bent radio source as it probes the environment and provide constraints onproperties of ambient medium and dynamics. Future radio surveys will detectmillions of bent radio sources, unleashing its great potential to study ICM/IGMand dynamics. On the other hand, it is still unclear whether all bent radiogalaxies are associated with groups and clusters. In this proposal, we focus onnearby (z<0.04) NATs to test the simple hypothesis that all NATs are in groupsor clusters. A sample of NATs not in known groups/clusters are selected for XMMobservations. For their proximity, they present best chances to invalidate thehypothesis, which would have important implications for the formation of NATs. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]