Constraints on thermal pressure, P, and distance from cloud to AGN, d, obtained by modelling the excitation of H₂ rotational levels with the PDR MEUDON code. The contours show formal regions that contain 0.683 probability distribution functions. The solid and dashed lines correspond to the estimates based on MCMC and vpfit result of H₂ fit (see Table 3), respectively. The marginalised probability distribution functions (along right and top axes) and the best-fit values (stars) are shown for MCMC results only for the sake of clarity. The black line with upwards arrows show the constraints from the H₂-H I transition, assuming the kinetic temperature is T ∼ 100 K, which is consistent with the observations.