Sampled one-dimensional (1D) marginal posterior cdfs (blue) of model I parameters for Neptune: a) mass of envelope m_env; b) envelope Luminosity L; c) mass of water m_water; d) mantle radius r_mantle; e) core radius r_core; f) Fe/Si_mantle; g) Mg/Si_mantle. Prior and posterior nearly completely overlap in g). The envelope metallicity Z_env (not shown) is fixed, Z_env = 0. The prior cdfs are plotted in red. Gray area in plots a)−d) represent independent literature estimates (see main text).