One-dimensional marginal constraints on Y_tot, θ_s and β for simulated low-noise data, for clusters with θ_s = 1.8 (solid lines), 4.5 (dashed lines) and 7.4 (dotted lines) arcmin and universal (γ,α,β), with the two-dimensional prior on Y_tot and θ_s and a uniform prior on β between 3.5 and 9.0 (α fixed to the correct, input value). Input values are shown as red lines. θ_s is in arcmin and Y_tot is in arcmin².