With a deep Chandra/HETGS exposure of WR 6, we have resolved emission lines whose profiles show that the X-rays originate from a uniformly expanding spherical wind of high X-ray-continuum optical depth. The presence of strong helium-like forbidden lines places the source of X-ray emission at tens to hundreds of stellar radii from the photosphere. Variability was present in X-rays and simultaneous optical photometry, but neither were correlated with the known period of the system or with each other. An enhanced abundance of sodium revealed nuclear-processed material, a quantity related to the evolutionary state of the star. The characterization of the extent and nature of the hot plasma in WR 6 will help to pave the way to a more fundamental theoretical understanding of the winds and evolution of massive stars.
Huenemoerder, David P.; Gayley, K. G.; Hamann, Wolf-Rainer; Ignace, Richard; Nichols, J. S.; Oskinova, Lidia M.; Pollock, A. M.T.; Schulz, Nobert S.; and Shenar, Tomer. 2015. Probing Wolf–Rayet Winds: Chandra/HETG X-Ray Spectra of WR 6. Astrophysical Journal. Vol.815(1). 29. https://doi.org/10.1088/0004-637X/815/1/29 ISSN: 0004-637X