A Pulsar Wind Nebula in the Oxygen-rich Supernova Remnant G292.0+1.8

Using the Chandra X-ray Observatory we have discovered a diffuse,center-filled region of hard X-ray emission within the young, oxygen-richsupernova remnant (SNR) G292.0+1.8. Near the peak of this diffuse emission liesa point-like source of X-ray emission that is well described by an absorbedpower-law spectrum with photon index $1.72\pm0.09$. This source appears to bemarginally extended; its extent of 1.3$^{\prime\prime}$ (FWHM) is greater thanthat of a nearby serendipitous X-ray source with FWHM = $1.1^{\prime\prime}$.This is strong evidence for the presence within SNR G292.0+1.8 of a youngrapidly-rotating pulsar and its associated pulsar wind nebula. From theunabsorbed, 0.2-4 keV band X-ray luminosity of the pulsar wind nebula ($L_X\sim4\times 10^{34} \rm ergs s^{-1}$), we infer a spin-down energy loss rate of$\dot E \sim 7\times 10^{36} \rm ergs s^{-1}$ for the still undetected pulsar.The pulsar candidate is $0.9^\prime$ from the geometric center of the SNR whichimplies a transverse velocity of $\sim$$770 (D/4.8 {\rm kpc}) (t/1600 {\rmyr})^{-1} \rm km s^{-1}$ assuming currently accepted values for the distanceand age of G292.0+1.8.Comment: 12 pages, including 3 postscript figs, LaTeX, ApJ Letter