Entropy (top panel), temperature, pressure, density, and He ii ionization fraction n_{He ii}/ (n_{He i} + n_{He ii} + n_{He iii}) (bottom panel) as function of the horizontal and vertical coordinates at time t = 1.40 × 10⁷ s, which corresponds to an expanding phase. Pseudo-streamlines are shown as black solid lines. Surfaces of constant Rosseland optical depth are shown by white lines: τ_R = 1 (solid line), τ_R = 10^-2 (dashed line), τ_R = 10^-4 (dashed-dotted line).