Modeled water production rate of 67P as a function of heliocentric distance. The red and blue solid lines correspond to the production rates from the radiative and conductive nuclei, respectively. In both cases, the aggregate size was assumed to be 1 mm. The constant heat conductivity was 0.002 Wm⁻¹K⁻¹. The water production rates derived by Fougere et al. (2016b) using ROSINA coma density measurements are plotted as gray squares for comparison.