A Bow Shock Nebula around a Compact X-Ray Source in the Supernova Remnant IC 443

We present Chandra spectra and high-resolution images of the hard X-ray feature in the southern edge of the supernova remnant (SNR) IC 443 that reveal a comet-shaped nebula of hard emission that contains a softer point source at its apex. We also present 20, 6, and 3.5 cm Very Large Array maps that clearly show the cometary nebula. Based on the radio and X-ray morphology and spectrum, and the radio polarization properties, we argue that this object is a synchrotron nebula powered by the compact source that is physically associated with IC 443. The spectrum of the soft point source is adequately but not uniquely fitted by a blackbody model [kT = 0.71 ± 0.08 keV, L = (6.5 ± 0.9) × 1031 ergs s-1]. The morphology of the nebula can be explained by the supersonic motion of the neutron star (VNS ≃ 250 ± 50 km s-1), which causes the relativistic wind of the pulsar to terminate in a bow shock and trail behind as a synchrotron tail. This velocity is consistent with an age of 30,000 yr for the SNR and its associated neutron star.