We present spatially-resolved analysis of the temperature and gas density profiles in 6 relaxed galaxy clusters at z = 0.4 - 0.54 using long-exposure Chandra observations .
We derived the total cluster masses within the radius r _ { 500 } assuming hydrostatic equilibrium but without assuming isothermality of the intracluster gas .
Together with a similar study based on the XMM-Newton observations ( Kotov & Vikhlinin ) , we obtained the mass and temperature measurements for 13 galaxy clusters at 0.4 < z < 0.7 spanning a temperature interval of 3 \text { keV } < T < 14 \text { keV } .
The observed evolution of the M - T relation , relative to the low-redshift references from the Chandra sample of Vikhlinin et al. , follows M _ { 500 } / T ^ { 3 / 2 } \propto E ( z ) ^ { - \alpha } , where we measure \alpha = 1.02 \pm 0.20 and \alpha = 1.33 \pm 0.20 for the spectroscopic and gas mass-weighted temperatures , respectively .
Both values are in agreement with the expected self-similar evolution , \alpha = 1 .
Assuming that the cluster mass for given temperature indeed evolves self-similarly , the derived slopes , \gamma , of the high-redshift M - T relation , E ( z ) M _ { 500 } \propto T ^ { \gamma } , are \gamma = 1.55 \pm 0.14 for T _ { spec } and \gamma = 1.65 \pm 0.15 for T _ { mg } .
Our results show that both the shape and evolution of the cluster M - T relation at z \simeq 0.5 is close to predictions of the self-similar theory .