Chandra discovery of a 300 kiloparsec X-ray jet in the gigahertz-peaked spectrum quasar PKS 1127-145

We have discovered an X-ray jet with Chandra imaging of the z=1.187 radio-loud quasar PKS 1127-145. In this paper we present the Chandra X-ray data, follow-up Very Large Array observations, and optical imaging using the Hubble Space Telescope Wide Field Planetary Camera 2. The X-ray jet contains 273+/-5 net counts in 27 ks and extends similar to30" from the quasar core, corresponding to a minimum projected linear size of similar to330 h(50)(-1) kpc. The evaluation of the X-ray emission processes is complicated by the observed offsets between X-ray and radio brightness peaks. We discuss the problems posed by these observations to jet models. In addition, PKS 1127-145 is a gigahertz-peaked spectrum (GPS) radio source, a member of the class of radio sources suspected to be young or "frustrated" versions of FR I radio galaxies. However, the discovery of an X-ray and radio jet extending well outside the host galaxy of PKS 1127-145 suggests that activity in this and other GPS sources may be long-lived and complex.