Observations of the 1 Mpc radio source 6C0905+3955 and the half-Mpc source 3C356

Extended Xray emission has been discovered around several distant powerfulradio galaxies. The emission is most likely due to inverse Compton scattering ofCMB photons by old radio synchrotron particles. The Xray emission thus tracesthe total input of relativistic electrons into the surroundings of the radiogalaxy, and the amount of energy injected, which will affect the gas propertiesof the host galaxy, group and cluster. All massive galaxies may have passedthrough such a phase. We propose to take a deep 60 ks observation of theexceptionally large 1 Mpc diameter, distant z1.88 radio galaxy, 6C0905+3955,and a 20 ks observation of the 1/2 Mpc diameter z1.08 radio galaxy 3C356. Bothsources are known from our previous work to have extended Xray emission along the radio source axis. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]