Probability distribution function for the inverse of the characteristic time scale (γ parameter) of the thin disc SFH, assuming a decreasing exponential shape. The right vertical blue dotted line indicates the γ value of the Mother Simulation used in the test. The left black dotted vertical line (γ = 0) indicates the value to be recovered by the test. In green we show the prior PDF assumed for the test (uniform distribution between −0.05 and 0.20). In red we show the resulting approximate posterior PDF P(γ|data).