6. Summary and conclusions
We have presented and discussed Beppo SAX observations of two high redshift clusters of galaxies: MS 2053.7-0449 at and RXJ 0152.7-1357 at .
The first object has been selected from the EMSS sample. No constraints on the metallicity can be derived from the present data; by fixing the abundance to 0.3 solar we measure a gas temperature with very high uncertainty ( keV).
The second cluster has been selected from the RDCS sample and is one of the most X-ray luminous system known at . It is characterized by a complex morphology (both in the optical and soft X-ray) with at least two cores, a gas temperature of keV and a metallicity of (68% confidence interval). A prominent iron line is clearly visible in the MECS spectrum.
In light of this new cluster temperature measurement at , we have discussed the high redshift () relationship and we have found that the limited data available so far can easily be accommodated with a non-evolving (or mildly evolving) relation. This result, when combined with the little observed evolution in the X-ray cluster abundance, gives support to cosmological models with a low density parameter (e.g. Borgani et al., 1999).
© European Southern Observatory (ESO) 2000
Online publication: December 17, 1999