Deep VLA imaging of pulsar-powered nebulae and the beaming fraction of young pulsars

Sensitive, high-resolution images of the fields of seven pulsar-powered nebulae were made with the VLA at 20 and 6 cm in order to investigate the extended emission from the nebulae and to explore any remaining point sources that could be candidates for a central pulsar powering the nebular emission. Several point sources were found but no compelling pulsar candidates were identified on the basis of their integrated properties. In the remnant 3C 58, the discovery of an elongated 'wisp' near the vicinity of a compact X-ray source is reported. This feature is argued to be a termination shock from the relativistic wind of an unseen pulsar. The beaming fraction of young pulsars in these nebulae is estimated to be 61 +/- 13 percent.