A ROSAT HRI observation of 3C 356: Further evidence for a distant intracluster medium

We report a 36-ks ROSAT HRI observation of the distant powerful radio galaxy 3C 356, which was detected in the PSPC, No point source is detected at the position of the radio galaxy at the flux expected from the PSPC observation, confirming that the PSPC source is extended. A weak extended source is detected in the HRI. We therefore rule out interpretations of the X-ray emission from this source as originating from the active nucleus, or a jet-cloud interaction. The emission observed with the PSPC most plausibly originates from the most distant intracluster medium yet detected in X-rays.