On the Interpretation of Prominence Spectra. V. The Emission Lines in Quiescent Prominences.

Abstract

view Abstract Citations (26) References (23) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On the Interpretation of Prominence Spectra. V. The Emission Lines in Quiescent Prominences. Jefferies, J. T. ; Orrall, F. Q. Abstract Observations are presented of emission-line total intensities and widths in the range XX for two quiescent prominences. In one of these prominences, total intensities are also given for emission lines in the range XX . From the total intensities it is found that (1) the excitation temperature describing the populations of the energy levels of Fe 1 is 3600 K; (2) the ratio of intensity of the 0 1 lines at X 7775 and X 8446 (known to be variable in astronomical sources) is 18(3) the electron kinetic temperature of the region emitting He 1 must be greater than 11000 K Estimates are made of the theoretical strengths of one line of He 1 and five lines of Fe 1. The shapes of the lines in the range XX 3600- 3800 are Gaussian to within the limit of error of measurement except for the higher Balmer lines of H 1 and the lines of He 1. These lines are all free from self-absorption. The line widths of H i correspond to atom kinetic temperature of about 8200 K, but this is an upper limit, since non-thermal motions also broaden the lines It is shown that the usual method of employing the widths of metal lines to correct for these non-thermal motions overcorrects in quiescent prominences, yielding too low a temperature; however, the hydrogen and metal line widths are consistent with atom kinetic temperatures between 6500 and 8200 K. In Paper IV the electron kinetic temperature was found to be 12500 K from continuum measures in one of these same prominences. The difference between the temperatures given by the two methods cannot be attributed to observational error. Although a real difference between the atom and electron kinetic temperatures may exist, it is suggested rather that these temperatures are averages over steep temperature gradients and the averages are weighted differently by the two methods. Publication: The Astrophysical Journal Pub Date: January 1962 DOI: 10.1086/147252 Bibcode: 1962ApJ...135..109J full text sources ADS | Related Materials (5) Part 1: 1958ApJ...127..714J Part 2: 1961ApJ...133..946J Part 3: 1961ApJ...133..963J Part 4: 1961ApJ...134..747J Part 6: 1963ApJ...137.1232J