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   PR # 42192
   We propose to measure the spectrum of a newly discovered galaxy
   cluster at a redshift of 0.818. This cluster was found as part of our
   ongoing identification work of X-ray sources near the North Ecliptic
   Pole in the ROSAT All-Sky Survey. There is only one other X-ray
   selected cluster known with a redshift greater than 0.8. An ASCA
   spectrum has previously been obtained for it. Our proposed
   observation combined with the existing data provide the first
   glimpses into the X-ray properites of clusters at these very early
   epochs. The very existence of massive clusters at these redshifts is
   problematic for some theories of the origin of structure in the
   Universe.
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