The Chandra X-ray galaxy clusters at z<1.4: constraints on the evolution of L _X −T−M _g relations

Abstract

We analyzed the luminosity-temperature-mass of gas (L _X −T−M _g ) relations for a sample of 21 Chandra galaxy clusters. We used the standard approach (β−model) to evaluate these relations for our sample that differs from other catalogues since it considers galaxy clusters at higher redshifts (0.4<z<1.4). We assumed power-law relations in the form $L_{X} \sim(1 +z)^{A_{L_{X}T}} T^{\beta_{L_{X}T}}$, $M_{g} \sim(1 + z)^{A_{M_{g}T}} T^{\beta_{M_{g}T}}$, and $M_{g} \sim(1 + z)^{A_{M_{g}L_{X}}} L^{\beta_{M_{g}L_{X}}}$. We obtained the following fitting parameters with 68 % confidence level: $A_{L_{X}T} = 1.50 \pm0.23$, $\beta_{L_{X}T} = 2.55 \pm0.07$; $A_{M_{g}T} = -0.58 \pm0.13$ and $\beta_{M_{g}T} = 1.77 \pm0.16$; $A_{M_{g}L_{X}} \approx-1.86 \pm0.34$ and $\beta_{M_{g}L_{X}} = 0.73 \pm0.15$, respectively. We found that the evolution of the M _g −T relation is small, while the M _g −L _X relation is strong for the cosmological parameters Ω _m =0.27 and Ω _Λ =0.73. In overall, the clusters at high-z have stronger dependencies between L _X −T−M _g correlations, than those for clusters at low-z. For most of galaxy clusters (first of all, from MACS and RCS surveys) these results are obtained for the first time.