We have detected weak soft X-ray emission from the Pulsar Wind Nebula trailing the high velocity star PSR 2224+65 ( the ‘ Guitar Nebula ’ ) .
This X-ray flux gives evidence of \gamma \sim 10 ^ { 7 } eV particles in the pulsar wind and constrains the properties of the post-shock flow .
The X-ray emission is most easily understood if the shocked pulsar wind is partly confined in the nebula and if magnetic fields in this zone can grow to near equipartition values .