Binary Yarkovsky coefficient as a function of the inclination for the secondary (red) and the primary (blue). The dashed black line is the critical inclination (i.e. arctan(r_p/a)), within which the eclipse always occurs during a mutual orbit. The values of parameters to calculate f_BY (Eqs. A.4 and A.5) are set as follows: a/r_p = 2.5, f_BY, s = 0.01 and f_BY, p = 0.001. In this figure, a positive value of f_BY represents the migration direction towards the synchronous orbit and a negative value denotes the opposite direction to the synchronous orbit.