Radial profile of the temperature, density, and opacity in the Σ4 simulation. Solid lines are from the analytical model with convective parts indicated by thicker lines. Dashed lines show the corresponding results of MBPL10. Left panel: when the core and envelope mass is 3.27 and 0.74 M_⊕, respectively (3.21 and 0.74 M_⊕ in MBPL10). Right panel: at a moment just before crossover. The core and envelope mass are 4.18 and 4.17 M_⊕, respectively (4.09 M_⊕ in MBPL10).