Estimated spectroscopic (black) and evolutionary (green) masses of each SB1’s unseen companion. The blue zone corresponds to the predicted mass range for Galactic stellar mass BHs and the red zone represents the same but for Galactic NSs (Belczynski et al. 2010; Fryer et al. 2014). The mass ranges for each target where main sequence stars cannot be discounted according to the spectral disentangling sensitivity (Sect. 3.1) are denoted by thick lines. Target names in boldface are the targets for which no companion could be extracted through spectral disentangling, and the other targets are those for which the nature of the extracted companion was ambiguous (Sect. 3.1).