Observational signatures of past mass-exchange episodes in massive binaries : The cases of HD17505 and HD206267

Mass and angular momentum exchanges through Roche Lobe Overflow interactions within close massive binaries are known to play an important role in the subsequent evolution of the components of such systems, and produce several observational signatures, such as asynchronous rotation and altered chemical compositions, that remain once the stars detach again. We have started to investigate these effects in a sample of massive O-star binaries that are thought to have previously experienced a Case A Roche Lobe Overflow episode. Using phase-resolved spectroscopy, we perform the disentangling of the optical spectra of the two stars. The reconstructed primary and secondary spectra are then analysed with the CMFGEN model atmosphere code to determine stellar parameters such as the effective temperatures, surface gravities and rotational velocities, and to constrain the chemical composition of the components. In this contribution, we present the results of our analyses of the triple system HD17505 ([O7V + O7V, P = 8.57 days] + O6.5III). We also present the first results of our analyses of the triple system HD206267 ([O6.5V + O9.5V,P = 3.71 days] + OB).