OWN Survey: results after seven years of high-resolution spectroscopic monitoring of Southern O and WN stars

BARBÁ, R.; GAMEN, R. C.; ARIAS, J.; MORRELL, N. I.; WALBORN, N.; MAÍZ APELLÁNIZ, J.; SOTA, A.; ALFARO, E.

Florianópolis

Congreso; XIV Latin American Regional IAU Meeting; 2013

IAU

We describe briefly the main results of the high-resolution spectroscopic monitoring survey of southern Galactic O- and WN-type stars. The high-resolution spectroscopic monitoring survey of O and WN stars (OWN Survey, Barbá et al. 2010) has completed seven years of sustained campaign, using observational facilities in Chile and Argentina. The selected sample corresponds to those stars for which there is no indication of multiplicity in the Galactic O-star Catalog (Maíz Apellániz et al. 2004) and the VII Catalogue of Galactic WR stars (van der Hucht 2001). We have collected almost 5000 spectra of about 240 O and WN stars. From that sample of 190 O-type stars, we have discovered 146 stars showing radial variations greater than 10 km/s, including 108 new systems, being 56 single-lined spectroscopic binaries, 43 double-lined spectroscopic binaries, and 9 multiple-lined binaries. The new orbital periods spanning from 1.5 to 2200 days. In this work, we present the main result of ``OWN Survey'': the determination of orbits for over fifty O-type spectroscopic binary systems, and the analysis of the spectral-type, luminosty, period, eccentricity, and mass-ratio distributions. This result is unprecedented in the context of massive binary stars, since we are almost doubling the number of Galactic O-type star systems with known orbits.