On the unresolved fine structures of the solar atmosphere. II - The temperature region 200,000 - 500,000 K

It was shown previously (Feldman, 1983) that the 30,000-200,000 K temperature solar plasmas behave differently than the chromosphere and corona, and it was concluded that while a small part of the emission detected may consist of 'classical' transition zone plasma, most of the emissions from these temperatures belong to a different entity termed 'unresolved fine structures'. In this paper these conclusions are extended to plasma emitted at higher temperatures, in the range of Te between 200,000 to 500,000 K. Using the Skylab spectrometer data on the Lyman continuum, C II, C III, O IV, O VI, and Mg X, it is shown that the properties of the solar atmosphere in these two temperature regions (30,000-200,000 K and 200,000-500,000 K, respectively) are similar.