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   PR # 41263
   The X-ray Luminosity-Temperature correlation of High redshitt
   clusters of galaxies combined with the knowledge of the redshift
   distribution of flux selected clusters offer new possibility to
   measure the density of the universe. Oukbir et al. have shown that,
   with a few high z clusters, and taking into account the evolution
   needed in the case of an open model, the uncertainty of the derived
   Lx-T normalisations is small enough to distinguish between a critical
   and an open universe. The objective of the present proposal is to
   measure the temperature of 2 high z clusters, A851 (z=0.402) and MS
   1621+2640 (z=0.426) to determine Lx-T correlation and constraint the
   value of the density of the universe.
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