Same as Fig. A.1, but for two models in which a neutron star with mass M = 2.0 M_⊙ is assumed. In model 26 the direct Urca process takes place at densities ρ ≥ 1.257 × 10¹⁵ g cm⁻³. To show the effect that this neutrino emission process has on the temperature evolution of the star, the direct Urca process is prohibited to take place in model 13 (label “no dUrca”). Figure 5 shows the neutrino luminosities as a function of temperature as used in NSCool for model 26.