Binary properties of Wolf-Rayet stars in nearby galaxies

Wolf-Rayet stars are the evolved descendants of massive O and early B stars, and it has recently been recognised that a high fraction of massive stars are born in close binary systems. This project will focus on establishing binary properties of Wolf-Rayet stars in nearby galaxies spanning a range of metallicities, based on a mixture of optical spectroscopic datasets (primarily ground-based from 8-10m class telescopes for WR stars in other galaxies) and X-ray observations (from Chandra T-ReX programme). These approaches are complementary since optical observations are sensitive to Doppler shifts in close binaries whereas X-ray datasets focus on colliding wind systems which sample somewhat larger separations. Initial targets are IC10 (metal-poor draft galaxy in Local Group) and the Tarantula region in the LMC.