| Abstract: | This paper mainly deals with the development of a method for the interpretation of eclipse observations in the extreme limb - lower chromosphere transition region. We compute line profiles emitted by a column of 1 cm2 cross section along the line of sight and, by integration, profiles and total (flash) intensities from a slice of 1 cm width beyond the Moon's edge, at various heights with respect to the solar limb. The solar models used are mentioned in Section 1; method and approximations are described in Section 2. Calculations have been made for some Fei lines with various equivalent widths (Table I); the results are discussed in Section 3. It appears that the method enables one to distinguish between the various models. Particularly line intensities just inside the limb are very important.We compared our computed results with some observations made by Houtgast (Section 4). The main conclusion is that a BCA-type temperature distribution alone does not agree with observations; we have to assume an excitation temperature of Holweger's type.Investigation performed at the Astronomical Institute, Utrecht; present address: Royal Belgian Observatory, 1180 Brussels. |
