T_merger as a function of χ_eff and M_chirp. The first row including three panels corresponds to the binary systems in which the companions are 10 M_⊙ BHs and there is no initial rotation for the He-rich stars. The other three rows are similar to the first row, but with different companions and initial rotation of the He-rich stars. The three columns refer to different metallicities of the He-rich stars, i.e., 0.01 Z_⊙, 0.1 Z_⊙ and Z_⊙. The colored dots correspond to the T_merger. Three gravitational events and one candidate with specific χ_eff and M_chirp from the observation of AdLIGO are shown on each panel. Black triangles correspond to binary systems whose T_merger is longer than the Hubble time.