EUV and radio spectrum of coronal holes
β Scribed by Franca Chiuderi Drago
- Publisher
- Springer
- Year
- 1980
- Tongue
- English
- Weight
- 677 KB
- Volume
- 65
- Category
- Article
- ISSN
- 0038-0938
No coin nor oath required. For personal study only.
β¦ Synopsis
From the intensity of 19 EUV lines whose formation temperature ~P ranges from 3 x I04 to 1.4 β’ 106, two different models of the transition region and corona for the cell-centre and the network are derived. It is shown that both these models give radio brightness temperatures systematically higher than the observed ones. An agreement with radio data can be found only with lines formed at low temperature (~P< 8.5 β’ 105) by decreasing the coronal temperature and the emission measure. The possibility of resolving the discrepancy by using different ion abundances has been also investigated with negative results.
π SIMILAR VOLUMES
The density dependence of solar EUV line intensity ratios from Mg VIII, Si VII, S IX and Si IX ions have been used to determine electron densities in the quiet Sun and coronal holes. The line intensity values have been computed using a model atmosphere of Kopp and Orrall (1976) in order to emphasize
Radio cool regions observed on strip scans of the Sun made at 2800 MHz with a 1.5 rnin arc fan beam are associated with X-ray coronal holes and are used to derive lower envelopes which are similar to spotless Sun drift curves. Fluxes are evaluated from the Ottawa-ARO solar patrol;.e.g, that of Coron