Far Ultraviolet Spectroscopic Explorer observations of the stellar winds of two O7 supergiants in the magellanic clouds

被引:28
作者
Fullerton, AW
Crowther, PA
De Marco, O
Hutchings, JB
Bianchi, L
Brownsberger, KR
Massa, DL
Morton, DC
Rachford, BL
Snow, TP
Sonneborn, G
Tumlinson, J
Willis, AJ
机构
[1] Univ Victoria, Dept Phys & Astron, Victoria, BC V8W 3P6, Canada
[2] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21286 USA
[3] UCL, Dept Phys & Astron, London WC1E 6BT, England
[4] Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V8X 4M6, Canada
[5] Osserv Astron Torino, I-10025 Pino Torinese, TO, Italy
[6] Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA
[7] NASA, Goddard Space Flight Ctr, Raytheon Infomat Technol Serv, Greenbelt, MD 20771 USA
[8] NASA, Goddard Space Flight Ctr, Sci Serv, Greenbelt, MD 20771 USA
[9] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA
基金
美国国家航空航天局;
关键词
stars : early-type; stars; individual; (Sk-67; degrees; 111; Sk; 80); winds; outflows;
D O I
10.1086/312787
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We compare the stellar wind features in far-UV spectra of Sk -67 degrees 111, an O7 Ib(f) star in the LMC, with Sk 80, an O7 Iaf+ star in the SMC. The most striking differences are that Sk 80 has a substantially lower terminal velocity, much weaker O VI absorption, and stronger S IV emission. We have used line-blanketed, hydrodynamic, non-LTE atmospheric models to explore the origin of these differences. The Tar-UV spectra require systematically lower stellar temperatures than previous determinations for O7 supergiants derived from plane-parallel, hydrostatic models of photospheric line profiles. At these temperatures, the O VI in Sk -67 degrees 111 must be due primarily to shocks in the wind.
引用
收藏
页码:L43 / L46
页数:4
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