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Far-UV FUSE spectroscopy of the OVI resonance doublet in Sand2 (WO)

Paul A. Crowther·A. W. Fullerton·D. J. Hillier·K. Brownsberger·L. Dessart·A. J. Willis·O. De Marco·M. J.·Barlow·J. B. Hutchings·D. L. Massa·D. C. Morton·G. Sonneborn
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Abstract

We present Far-Ultraviolet Spectroscopic Explorer (FUSE) spectroscopy of Sand 2, a LMC WO-type Wolf-Rayet star, revealing the OVI resonance P Cygni doublet at 1032-38A. These data are combined with HST/FOS ultraviolet and Mt Stromlo 2.3m optical spectroscopy, and analysed using a spherical, non-LTE, line-blanketed code. Our study reveals exceptional stellar parameters: T*=150,000K, v_inf=4100 km/s, log (L/Lo)=5.3, and Mdot=10^-5 Mo/yr if we adopt a volume filling factor of 10%. Elemental abundances of C/He=0.7+-0.2 and O/He=0.15(-0.05+0.10) by number qualitatively support previous recombination line studies. We confirm that Sand 2 is more chemically enriched in carbon than LMC WC stars, and is expected to undergo a supernova explosion within the next 50,000 yr.

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Paul A. Crowther, A. W. Fullerton, D. J. Hillier, K. Brownsberger, L. Dessart, A. J. Willis, O. De Marco, M. J., Barlow, J. B. Hutchings, D. L. Massa, D. C. Morton, G. Sonneborn. 2000-05-03. Far-UV FUSE spectroscopy of the OVI resonance doublet in Sand2 (WO). https://arxiv.org/abs/astro-ph/0005056

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