Tomographic Separation of Composite Spectra of O-Type Stars

We have analyzed UV photospheric lines of three O-type binaries (AO Cas, Plaskett’s Star, and 29 UW CMa) by means of tomographic and cross-correlation analyses, with the goal of estimating the physical properties of the individual stars. The tomographic techniques allowed us to estimate T eff and log g the luminosity ratio, and rotational velocities. The mass ratios were obtained from a cross-correlation technique, applied to spectral regions in which preliminary tomography shows the secondary has strong photospheric line features.