Cosmological constraints in the (Ω_m,σ₈) plane obtained from Eqs. (6) and (7) by using predictions from the model by Eke et al. (2001). The confidence contours at 1,2,3σ on 2 parameters (solid contours) are displayed. The combined likelihood with the probability distribution provided from the cluster gas mass fraction method is shown in red. The dashed green line indicates the power-law fit . The best-fit results are quoted in Table 6. A relative logarithmic scatter of 0.139 (see Sect. 6) is considered in the models. Systematic uncertainties on c₂₀₀ and f_gas(<R₅₀₀) as quoted in Table 4 are also propagated. (Left) From the subsample of 26 clusters satisfying the condition (r_s + ϵ_rs) < R_sp; (center) from the subsample of the LEC objects; (right) from all the 44 clusters.