Temperature-density structure of a suite of BH* models. We show the electron temperature (solid lines) and electron density (dashed lines) profiles for models corresponding to log₁₀U = −3, v_turb = 210 km s⁻¹ and Z/Z_⊙ = 0.01, for a wide range of hydrogen densities. All models are characterized by a hot (∼16 000 K; see Fig. D1 for the temperature with different choices of ionization parameter) and dense ionized region whose temperature and density abruptly drop at an ionization front, its radius dependent on density, and a thermalized outer layer of ∼6000–7500 K.