WR 146 – observing the OB-type companion |
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| Authors: | S M Dougherty P M Williams D L Pollacco |
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| Institution: | Dominion Radio Astrophysical Observatory, PO Box 248, White Lake Road, Penticton, British Columbia V2A 6K3, Canada;Department of Physics and Astronomy, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada;Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ;Department of Pure and Applied Physics, Queen's University, David Bates Building, Belfast BT7 1NN |
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| Abstract: | We present new radio and optical observations of the colliding-wind system WR 146 aimed at understanding the nature of the companion to the Wolf–Rayet (WR) star and the collision of their winds. The radio observations reveal emission from three components: the WR stellar wind, the non-thermal wind–wind interaction region and, for the first time, the stellar wind of the OB companion. This provides the unique possibility of determining the mass-loss rate and terminal wind velocity ratios of the two winds, independent of distance. Respectively, these ratios are 0.20±0.06 and 0.56±0.17 for the OB-companion star relative to the WR star. A new optical spectrum indicates that the system is more luminous than had been believed previously. We deduce that the 'companion' cannot be a single, low-luminosity O8 star as suggested previously, but is either a high-luminosity O8 star, or possibly an O8+WC binary system. |
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| Keywords: | stars: individual: WR 146 stars: Wolf–Rayet radio continuum: stars |
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