Observations of pulsar wind nebulae

C.Y. Hui (MPE, Germany) , Werner Becker (MPE, Germany), Hsiu-Hui Huang (MPE, Germany)

In searching for diffuse X-ray emission around a variety of pulsars, we have discovered trail-like nebulae associated with PSRs J2124-3358 and J1509-5850. Examining the diffuse emission, we found that the observed X-rays are non-thermal in nature. Modeling the nebular emission with the one-zone model, we found that the observed X-rays are inline with the emission originating from accelerated particles in the post shock flow. In searching for radio counterparts, we have discovered a radio nebula associated with PSR J1509-5850 which is apparantly longer than its X-ray counterpart. This is consistent with the scenario of sychrotron cooling. The X-ray nebula of PSR J2124-3358 is the first time that extended emission from a solitary millisecond pulsar is detected. In contrast to a typical pulsar wind nebula, the X-ray nebula of PSR J2124-3358 appears to be highly asymmetric and significantly deviated from the direction of the pulsar's velocity.