Temperature structure for models with a fixed effective temperature T_eff = 1, 2, and 3 × 10⁷ K (upper, middle, and bottom panel, respectively). Different chemical compositions are presented by different line styles given in the legend. Two relative luminosities are presented by red lines for l = 0.95 in each figure panel and by black lines for l = 0.05, l = 0.13, l = 0.65 in the upper, middle, and bottom panel, respectively.