The Chandra X-ray Observatory resolves the X-ray morphology and spectra ofa jet in PKS 0637-752

The core-dominated radio-loud quasar PKS 0637-752 (z = 0.654) was the first celestial object observed with the Chandra X-Ray Observatory, offering the early surprise of the detection of a remarkable X-ray jet. Several observa tions with a variety of detector configurations contribute to a total expos ure time with the Chandra ACIS of about 100 ks. A spatial analysis of all t he available X-ray data, making use of Chandra's spatial resolving power of about 0".4, reveals a jet that extends about 10 " to the west of the nucle us. At least four X-ray knots are resolved along the jet, which contains ab out 5% of the overall X-ray luminosity of the source. Previous observations of PKS 0637-752 in the radio band had identified a kiloparsec-scale radio jet extending to the west of the quasar. The X-ray and radio jets are simil ar in shape, intensity distribution, and angular structure out to about 9", after which the X-ray brightness decreases more rapidly and the radio jet turns abruptly to the north. The X-ray luminosity of the total source is lo g L-X approximate to 45.8 ergs s(-1) (2-10 keV) and appears not to have cha nged since it was observed with ASCA in 1996 November. We present the resul ts of fitting a variety of emission models to the observed spectral distrib ution, comment on the nonexistence of emission lines recently reported in t he ASCA observations of PKS 0637 - 752, and briefly discuss plausible X-ray emission mechanisms.