Synchronisation time scale (yr) of the radiative (RZ) and convective (CZ) zones as a function of the tidal period (days) in logarithmic scales. The cyan line designates the synchronization time scale computed numerically with the model of the uniformly rotating spherical shell using Eq. (82). This line is solid (dashed) in regions where the radiative layer is torqued away from (towards) synchronization. The dotted black line designates the synchronization time scale resulting from the torque derived analytically in the zero-frequency limit. Red and blue dashed lines correspond to the case of the convective interior with constant tidal quality factors set to Q = 10³ and Q = 10⁵, respectively.They are plotted using Eq. (81).