Posterior distributions for all the parameters of the chemical-equilibrium retrieval, for KELT-23 Ab. Off-diagonal plots report the 2D posterior distribution for pairs of parameters with the 1 σ-, 2 σ-, and 3 σ-confidence intervals. On-diagonal plots report the posterior distributions of each parameter marginalised over the remaining parameters. The blue lines represent the predicted values for some parameters and the red lines represent the median of the posterior distributions.