| タイトル | Far-Ultraviolet Temperature Diagnostics for Hot Central Stars of Planetary Nebulae |
| 著者（英） | Sonneborn, G.; Herald, J.; Ipin, R. C. |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2007-01-07 |
| 言語 | eng |
| 内容記述 | The effective temperature of hot central stars of planetary nebulae is usually determined from the ratios of optical He II lines. However, far-ultraviolet spectra from the FUSE satellite of several hot (T(sub eff) > 70,000 K) hydrogen-rich central stars have stellar features that imply a significantly hotter effective temperature than that determined from He II. There are many stellar features in the long wavelength portion of the FUSE spectrum. These include O VI 1146-47, F VI 1039.5, FeVII 1118.6, 1141.4, FeVI 1120.9, 1131.5, and NiVI 1124.2, 1148.2. The strong FVI 1139.5 line is of interest because of the large overabundance (over 100X solar) of F in some PG1159 stars reported recently by Werner et al. (2005). Modeling these spectral features may provide an method for measuring the effective temperature of these stars independent of the He II lines. An example of HD 200516, the central star of NGC 7009 (T(sub eff)= 82000 K from He II vs 95000 K from Far-W metal lines) is presented. |
| NASA分類 | Astrophysics |
| 権利 | Copyright |
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