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   PR # 42200
   We propose ASCA observations of three clusters of galaxies which have
   been recently detected in the Sunyaev-Zel'dovich (SZ) effect: A611,
   A697 and A2261. These clusters were chosen so that selection effects
   that arise in determining the cosmic distance scale using SZ effect
   and X-ray data are tightly controlled. The ASCA data will provide the
   essential information on the temperature of the intracluster hot gas
   for the application and testing of the distance measuring technique.
   The proposed observations represent the first rigorous attempt to
   measure the selection effect biases in the SZ/X-ray distances, which
   must be understood before the distance-measuring techniques (which
   can, in principle, be applied at large redshifts) can be used with
   confidence.
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