A ROSAT SEARCH FOR X-RAY-EMISSION FROM QUASAR HOST CLUSTERS

We report the results of a search for x-ray emission from quasar host clusters at moderate redshift using the ROSAT HRI. We detect no emissi on from the host clusters of 3C 263 (z=0.646) and PKS 2352-34 (z=0.706 ) to 3 sigma limits of 3.26 and 2.86x10(44) erg s(-1) respectively (H- 0=50, q(0)=1/2) for clusters with r(core)=125 kpc and T=5 keV. These L imits show that these quasar host clusters are not substantially more x-ray luminous than optically or x-ray selected clusters of similar ri chnesses at z greater than or equal to 0.5. We also report the possibl e detection of a clump of x-ray emitting gas coincident with the brigh test radio lobe of 3C 263. This may be evidence for the existence of a clumpy ICM in the host cluster of 3C 263. (C) 1995 American Astronomi cal Society.