High Dispersion SWP Spectra of Yellow and Red Giants
Abstract
We propose to continue our program, in collaboration with 0. Engvold and C. Jordan, to obtain 15 hour SWP high dispersion spectra of the few late-type giants and supergiants observable by IUE. On the basis of low dispersion SWP spectra, Linsky and Haisch (1979) and Simon et al. (1981) have proposed a boundary in the HR diagram separating stars with and without detected emission from 10^5 K plasma. We propose detailed studies of 4 stars -- 2 on either side of the boundary. Our scientific objectives are to derive the distributions of temperature and density for the chromospheres and transition regions (if present). We plan to do this by constructing model chromospheres and transition regions using lines of Mg II, Si II, C II, Si III, C III, C IV, and N V, by an emission measure analysis, and using density-sensitive line ratios. These models will be used to assess the energy balance in order to learn about the outer atmosphere heating mechanisms and wind acceleration mechanisms.
- Publication:
-
IUE Proposal
- Pub Date:
- 1982
- Bibcode:
- 1982iue..prop.1133L