Analysis of extreme-ultraviolet spectroheliograms of solar prominences

✍ Scribed by Mitsuo Kanno; George L. Withbroe; Robert W. Noyes

• Publisher: Springer
• Year: 1981
• Tongue: English
• Weight: 703 KB
• Volume: 69
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00149997

✦ Synopsis

The optical depth at the head of the Lyman continuum, rr~, is determined at a number of positions in three hedgerow prominences using spectroheliograms (5" x 5" resolution) of C m h 977, LC )t 896, and O Iv h 554 observed with the Harvard experiment on Skylab. At heights greater than 10" above the limb the maximum value of rH is 30 to 50, which occurs at the central part of the prominences. For one of the prominences the determination of Zla is found to be consistent with data from spectroheliograms of Mg x h 625. The degree of ionization of hydrogen is estimated from the intensity of LC h 896 at rH >> 1. In the central part of a model prominence Np/Nm-< 1.9 for a reasonable range of the electron densities, where Np and Nm are the proton density and the neutral hydrogen density, respectively.