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   PR # 12147
    We propose to measure the X-ray temperatures and iron content of the
    hot intracluster gas in a distant,luminous cluster of galaxies,MS0450
    -0305.This cluster,one of the most X-ray luminous clusters in the Uni
    verse,is the most distant knowncluster in which these quantities can
    be reliably measured.By comparing it to nearby clusters of similar X-
    ray luminosity,we will test models for the evolution of clusters of
    galaxies.We will also estimate the cluster mass & the mass of process
    ed material contributed by member galaxies.Our goals are attainable
    because this cluster is bright,it is chosen from a well-defined,X-ray
    selected sample of clusters,it is distant enough to show evolution
    according to current theories,and we have supporting data from ROSAT,
   optical spectroscopy,and the V
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