SMaSH+ physical properties of O-Stars pairs

The Southern Massive Stars at High Angular Resolution survey (SMASH+) use interferometric and high-angular resolution techniques to detect companions at intermediate separations, from about 1 milliarcsec to 8 arcsec, a domain that so far has remained largely unexplored. In this paper, we convert the angular separations and magnitude contrasts into physical units, i.e. projected physical separations and mass ratios.

We also derive the sensitivity of the survey for various physical and orbital parameters and we investigate the orbital separation and mass distributions. We develop a spectral type/luminosity class - H-band luminosity - mass calibration based on existing grids of physical parameters of O stars and we use these to obtain the photometric distance to each system. We also derive the individual masses of the primaries and of each detected companion.