Estimated mass ranges for the unseen companions in the SB1 systems, computed from the spectroscopic (black lines) and evolutionary (green lines) masses of the visible stars. The red area indicates the predicted mass range for Galactic NSs, and the blue area represents the predicted mass range for Galactic stellar BHs (Belczynski et al. 2010; Fryer et al. 2014), and where non-degenerate secondaries could have been retrieved. The diamonds and triangles represent the minimum mass that we are able to extract using spectral disentangling according to our simulations (Sect. 3.2).