Astronomy and Astrophysics – Astrophysics
Scientific paper
2004-04-12
Astrophys.J. 610 (2004) 1021-1037
Astronomy and Astrophysics
Astrophysics
47 pages, 15 figures (reduced size). Accepted for publication in ApJ. A postscript version with full res. figs is available fr
Scientific paper
10.1086/421769
We present quantitative studies of 8 late O and early B-type supergiants in the Magellanic Clouds using far-ultraviolet FUSE, ultraviolet IUE/HST and optical VLT-UVES spectroscopy. Temperatures, mass-loss rates and CNO abundances are obtained using the non-LTE, spherical, line-blanketed model atmosphere code of Hillier & Miller (1998). We support recent results for lower temperatures of OB-type supergiants as a result of stellar winds and blanketing, which amounts to ~2000 K at B0 Ia. In general, H$\alpha$ derived mass-loss rates are consistent with UV and far-UV spectroscopy, although from consideration of the SIV $\lambda\lambda$1063-1073 doublet, clumped winds are preferred over homogenous models. AV 235 (B0 Iaw) is a notable exception, which has an unusually strong H$\alpha$ profile that is inconsistent with the other Balmer lines and UV wind diagnostics. We also derive CNO abundances for our sample, revealing substantial nitrogen enrichment, with carbon and oxygen depletion. Our results are supported by comparison with the Galactic supergiant HD 2905 (BC0.7 Ia) for which near-solar CNO abundances are obtained. This bolsters previous suggestions that ``normal'' OB-type supergiants exhibit atmospheric compositions indicative of partical CNO processing.
Crowther Paul A.
Evans John C. Jr.
Fullerton Alex W.
Hillier Desmond John
No associations
LandOfFree
Quantitative studies of the Far-UV, UV and optical spectra of late O and early B-type supergiants in the Magellanic Clouds does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Quantitative studies of the Far-UV, UV and optical spectra of late O and early B-type supergiants in the Magellanic Clouds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quantitative studies of the Far-UV, UV and optical spectra of late O and early B-type supergiants in the Magellanic Clouds will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-608767