Temperature structure for models with a fixed surface gravity equal to the measured value log(g) = 14.34, which corresponds to an NS mass 1.9 M_⊙ and a radius of 12.4 km (middle panel; Nättilä et al. 2017), and the errors are log(g) = 13.70 (upper panel), and log(g) = 14.90 (bottom panel). The 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 the upper and middle panels, for l = 0.3 in the bottom panel, and by the black lines for l = 0.05, l = 0.13, l = 0.65 in the upper, middle, and bottom panel, respectively.