Interpretation of the solar spectrum 300-900 nm - II. Fe I lines of excitation potential 0.00-1.01 eV: use of new oscillator strengths of 0.5 per cent accuracy

Abstract

The solar spectrum is interpreted using the new Oxford oscillator strengths for Fei lines of excitation potential 0.00—1.01 eV of 0.5 per cent accuracy. The analysis is used to test the accuracy of the oscillator strengths, and to derive information about the solar atmosphere. Abundances and microturbulence values are deduced using the Vernazza, Arnett & Loeser model atmosphere and three other model atmospheres. Using the Vernazza et al model atmosphere at m= 1-0, for the OeV lines the microturbulence is 0.78 km/s and the abundance log ^4 = 7.440, and for leV Unes the values are 0.61 km/s and logv4 = 7.479, implying an increase in microturbulence with height. Microturbulence values for the integrated disk spectrum are 1.05 and 0.98 km/s respectively. Until an acceptable model atmosphere is available the solar abundance of iron derived from the Fe i spectrum, will remain uncertain by at least 0.2 dex. Damping coefficients are given for seven strong lines, and a curve of growth for the solar spectrum at ju = 1.0 is also given. 1