Evolution of the surface temperature for a neutron star with vortex creep (long-dashed lines), rotochemical heating (solid lines), and passive cooling (dotted lines). All curves correspond to stars with the A18 + δυ + UIX* EOS and modified Urca reactions. The error bar shows the temperature measured for the MSP J0437-4715 and the arrows show the upper limits on the thermal emission for specific pulsars. Top panel: the curves correspond to MSPs with mass M = 1.76   M_⊙, magnetic field B = 2.8 × 10⁸ G, and initial temperature T = 10⁸ K. Bottom panel: the curves correspond to classical pulsars with mass M = 1.4   M_⊙, magnetic field B = 2.5 × 10¹¹ G, and initial temperature T = 10¹¹ K. The abscissa corresponds to the spin-down time (t_s = Ω / 2 | Ω̇ | ). The initial periods for rotochemical heating are labeled on each curve.