%0 Journal Article
%T X-ray emission from the Wolf-Rayet bubble S308
%A J. A. Toal¨¢
%A M. A. Guerrero
%A Y. -H. Chu
%A R. A. Gruendl
%A S. J. Arthur
%A R. C. Smith
%A S. L. Snowden
%J Physics
%D 2012
%I arXiv
%R 10.1088/0004-637X/755/1/77
%X The Wolf-Rayet (WR) bubble S 308 around the WR star HD 50896 is one of the only two WR bubbles known to possess X-ray emission. We present XMM-Newton observations of three fields of this WR bubble that, in conjunction with an existing observation of its Northwest quadrant, map most of the nebula. The X-ray emission from S 308 displays a limb-brightened morphology, with a central cavity ~22 arcmin in size and a shell thickness of ~8 arcmin. This X-ray shell is confined by the optical shell of ionized material. The spectrum is dominated by the He-like triplets of NIV at 0.43 keV and OVII at 0.57 keV, and declines towards high energies, with a faint tail up to 1 keV. This spectrum can be described by a two-temperature optically thin plasma emission model (T1 ~ 1.1x10^6 K, T2 ~ 13x10^6 K), with a total X-ray luminosity ~2x10^33 erg/s at the assumed distance of 1.5 kpc.
%U http://arxiv.org/abs/1201.2879v4