entire remnant (Kahn et al. 1985; Lu and Aschenbach 2000). Even the bright radio filament detected by Bietenholz, Frail and Hankins (1991) shows no corresponding enhancement in our X-ray image, although more constraining limits will be derivable from ACIS observations.

The compact X-ray source near the pulsar was first recognized by Kellogg et al. (1973) as having a harder spectrum. Subsequent observations with increasing angular resolution (Harnden et al. 1985 and references therein; Ögelman, Finley, and Zimmermann 1993; Markwart and Ögelman 1998) localized the compact nebula to a region $\sim 2^{\prime}$ in extent roughly centered on the pulsar. Ögelman et al. (1993) used the nominal PSF of the ROSAT PSPC and an [*ad hoc*]{} model for the surface brightness of the diffuse emission to attempt a deconvolution of the pulsar and its nebula and to obtain spectral fits to the two components. They found that a blackbody effective temperature of 0.15 keV adequately characterized the point source, while the extended emission exhibited a power law spectrum with a photon index of $\sim 2.0$; a column density of $N_H = 1 \times 10^{20}$ cm$^{-2}$ is marginally consistent with both components. Markwardt and Ögelman (1998) subsequently revised the division of the flux 