BeppoSAX observations of two high redshift clusters of galaxies: RXJ0152.7-1357 and MS2053.7-0449

TL;DR

This study presents X-ray observations of two high-redshift galaxy clusters, revealing their temperatures, metallicities, and morphologies, and discusses implications for cosmological models based on their luminosity-temperature relation.

Contribution

First detailed X-ray analysis of two high-redshift clusters with implications for cluster evolution and cosmology.

Findings

RXJ0152.7-1357 has a temperature of 6.46 keV and complex morphology.

MS2053.7-0449's temperature is 6.7 keV with large uncertainties.

Results support a non-evolving or mildly evolving luminosity-temperature relation.

Abstract

We present X-ray observations of two high redshift clusters of galaxies carried out with the BeppoSAX satellite. One cluster, RXJ0152.7-1357 at z = 0.83, was selected from the ROSAT Deep Cluster Survey sample, as one of the most X-ray luminous systems known at z>0.5. The optical and ROSAT-PSPC data show a complex morphology with at least two cores. Our SAX observations yield a gas temperature kT = 6.46^{+1.74}_{-1.19} keV and a metallicity A = 0.53^{+0.29}_{-0.24}, with a prominent iron K(alpha) line. The second cluster, MS2053.7-0449 at z = 0.58, was selected from the EMSS sample. Given the poor statistics no constraints on the metallicity can be derived from the present data. Large uncertainties are associated to the gas temperature (kT = 6.7^{+6.8}_{-2.3} keV), which has been obtained after fixing the abundance to 0.3 solar. Combining these results with those obtained for similarly high redshift (z >= 0.5) clusters of galaxies with broad band X-ray spectra, we discuss the high redshift L(bol) - T relationship. The data can easily be accommodated with a non-evolving (or mildly evolving) L(bol) - T relation, a result which, when combined with the little observed evolution in the bulk of the X-ray cluster population, gives support to low Omega cosmological models.