X-RAY EMISSION FROM THE WOLF-RAYET BUBBLE S 308

作者：Toala J A^*; Guerrero M A; Chu Y H; Gruendl R A; Arthur S J; Smith R C; Snowden S L

来源：Astrophysical Journal, 2012, 755(1): 77.

DOI：10.1088/0004-637X/755/1/77

• ISM: bubbles
• ISM: individual objects (S 308)
• stars: individual (HD 50896)
• stars: winds, outflows
• stars: Wolf-Rayet
• X-rays: individual (S 308)

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 similar to 22%26apos; in size and a shell thickness of similar to 8%26apos;. This X-ray shell is confined by the optical shell of ionized material. The spectrum is dominated by the He-like triplets of N VI at 0.43 keV and O VII at 0.57 keV, and declines toward high energies, with a faint tail up to 1 keV. This spectrum can be described by a two-temperature optically thin plasma emission model (T-1 similar to 1.1 x 10(6) K, T-2 similar to 13 x 10(6) K), with a total X-ray luminosity similar to 2 x 10(33) erg s(-1) at the assumed distance of 1.5 kpc.

• 出版日期2012-8-10