Elemental Abundance Analyses with DAO Spectrograms. XXXV. On the Iron Abundances of B and A Stars

摘要

I compared the results of LTE fine analyses for B and A stars based on the newer "precise and accurate" Fe II gf values of Melendez & Barbuy (MB) with those based on the relatively recent major critical compilation of Fuhr & Wiese (FW). Only nonblended Fe II lines with both FW and MB gf values for 34 B and A stars with equivalent widths derived from high dispersion, high (>200) signal-to-noise ratio Dominion Astrophysical Observatory spectra were used. For most stars the standard deviations of the abundances derived from Fe II lines decrease slightly with the MB values, which is the signature of better consistency among the gf values. Then, for stars with many Fe I lines, I performed analyses using all lines with FW gf values and those with only A and B quality gf values and found minor improvements in the latter case. However, the abundances and micro-turbulences derived from Fe I lines are in better agreement with the Fe II FW results. The discrepancy between the results for Fe I FW and Fe II MB values could be due to NLTE effects on Fe I. A more limited comparison is made with the recent theoretical values of Deb & Hibbert which, when used, show a greater scatter of the derived Fe II gf values and smaller abundances than those obtained with the MB gf values.