Survival probability of the triple system as a function of the natal kick velocity (V_k) imparted to the newborn NS. The basic model is plotted by a solid line for a presupernova inner binary with a He star with M_1,pre = 2.0 M_⊙ at the presupernova stage, and an MS companion star with a mass of 2.0 M_⊙ in an initial orbital period (P_orb,in) of 2 days, while the tertiary star has a mass of 1.3 M_⊙ and the outer orbit has a period of 30 yr. We set the newborn NS mass to 1.4 M_⊙. The dashed line is plotted for the alternative case with M_1,pre = 1.7 M_⊙, and the dashed–dotted line for the case with P_orb,in = 5 days.