Thermodynamic models and fine structure of prominences
β Scribed by O. Engvold
- Publisher
- Springer
- Year
- 1980
- Tongue
- English
- Weight
- 246 KB
- Volume
- 67
- Category
- Article
- ISSN
- 0038-0938
No coin nor oath required. For personal study only.
β¦ Synopsis
Observed Ha brightness versus size of emission substructures of quiescent prominences are compared with values predicted from thermodynamical models. The measured size of an emission element of a given brightness is substantially less than the theoretical value.
Two possible causes for the discrepancy are suggested: (1) The partial filling of a recording aperture, due to the prominence fine structure, may affect the measurements seriously. Caution is therefore urged against using face values of observed brightness vs ratios in model calculations in cases of partly optically thick lines. (2) Changes of individual fine structure elements on a time scale of a few minutes implies that the prominence plasma may be in a non-stationary radiative state.
π SIMILAR VOLUMES
Faint, Doppler shifted, emission features are detected in high resolution spectra of limb prominences. Their average line-of-sight velocity is about 3 x 106 cm s i, their average life time is 300 s, and their angular sizes are ~<10 s cm in our spectrograms. The emission line width of the spectral fe
A quiescent prominence has been observed with the MSDP spectrograph at the Pic du Midi Observatory. He profiles are obtained simultaneously in a 2D field, allowing a statistical analysis. The standard deviations of Doppler shifts and line widths are investigated as functions of the line intensity. T
The Ca Β§ K line of the quiescent prominence of 15 October 1969 observed at the Abastumani Astrophysical Observatory of the Academy of Sciences of Georgia, U.S.S.R. is studied in detail. The behaviour of various fragments of the prominence with the line-of-sight Doppler velocities is investigated for