Coronal Emission from Solar Flares.
Abstract
The spectra of limb flares almost invariably show intense radiation of the coronal lines of Caxv, CaxilI and ArxIv, as well as strong continuum. The electron density in the flare condensation may be obtained on the assumption that the continuum is due to Thompson scattering. Calculation of the excitation of Caxv shows that the ratio of line to continuum emission is also a function of density. The results of these two determinations are compared for a number of flares. The effect of filamentation may also be evaluated. Recombination radiation from Hell in such condensations is also a function of density, and gives us a third determination. Densities ranging from 5 X 10~ to 2 X lO~~ electrons per cm3 are found. In general, the line: continum ratio depends on abundance. Approximate abundances for calcium, argon, iron, and helium are given.
- Publication:
-
The Astronomical Journal
- Pub Date:
- 1963
- DOI:
- 10.1086/109029
- Bibcode:
- 1963AJ.....68Q..82Z