An X-Ray Jet Discovered by Chandra in the z =4.3 Radio-selected Quasar GB 1508+5714

Abstract

We report the Chandra discovery of an X-ray jet associated with the zp4.3 radio-loud quasarGB1508?5714. The jet X-ray emission peaks ∼2? to the southwest of the quasar core.We present archival Hubble Space Telescope Wide Field Planetary Camera 2 data of the quasar field that show no optical emission at the location of the X- ray jet. We discuss possible emission mechanisms and give constraints to the magnetic field and energy densities for synchrotron radiation or for Compton scattering of the cosmic microwave background radiation as the jet X- ray emission process.