1980/05/01 by D. A. Landman
Physics and Astronomy · #Solar and Space Plasma Dynamics #Ionosphere and magnetosphere dynamics
paper · doi:10.1086/157944
High-dispersion measurements of the line profiles of the Ca(+) lines at 8542 and 8498 A and the He 4471-A, Ti(+) 4468-A line pair in the spectra of quiescent solar prominences are presented. The measured Ca(+) and He line profiles are found to be accurately described by the two-component model of Landman et al. (1977) and Landman and Mongillo (1979) in which the prominence along the line of sight consists of a low-temperature region surrounded by high-temperature material representing contributions from the prominence/corona interface; the Ti(+) lines are too weak to distinguish among different models. The Ca(+) data allow a constant infrared line source function for the low-temperature region of 50,000 ergs/sq cm per sec per ster per A to be calculated, which is in disagreement with the previous Ca(+) excitation equilibrium calculations but is consistent with generally accepted values of the electron density and temperature. The integrated intensity ratio of 0.048 between Ti(+) and He emission indicates a low-temperature region temperature of 6620 K and microturbulence of 5.1 km/sec and high-temperature microturbulence of 11 km/sec for Ca(+) and 20 km/sec for He. The results exclude macroturbulence as a possible explanation of the generally observed wing enhancements.