M_gas − T scaling relation and the posterior distributions of the scaling relation parameters. Left: gas mass (M_gas), temperature (T), and redshift (z) measurements of the ℒ_det > 15, ℒ_ext > 15 sample and the best-fit scaling relation models. The light-red shaded area indicates the 1σ uncertainty of the mean of the log-normal model (see Eq. (5)) and the dashed red line indicates the best-fit standard deviation around the mean. Orange diamonds indicate median temperature measurements obtained from clusters between gas mass quantiles. Right: parameter constraints of the M_gas − T relation obtained from the second half of the MCMC chains. Marginalized posterior distributions are shown on the diagonal plots and the joint posterior distributions are shown on off-diagonal plots. Red dashed vertical lines indicate 32th, 50th, and 68th percentiles and contours indicate 68 and 95% credibility regions.