Absolute transition probabilities for the a6D y6P° multiplet (#8) of Fe II
Department of Physics, University of Wisconsin-Madison, Madison, WI 53706, U.S.A.
Send offprint request to: K.L. Mullman
Accepted: 2 July 1996
We report the first laboratory measurement of absorption oscillator strengths (f-values) for 6 VUV () transitions of the multiplet (#8) in Fe II. We have also reconfirmed a recent measurement of the f-value of the Fe II resonance line at . These measurements are made with the high sensitivity absorption experiment at the University of Wisconsin-Madison. Measurements are also made on UV () lines in Fe II with accurately known f-values in order to construct a reliable curve of growth for the experiment. Diffusive cooling of ions in the negative glow of the hollow cathode discharge, which serves as an absorbing sample, results in a non-Maxwellian ion velocity distribution. A satisfactory curve of growth is generated using a full Voigt profile with an artificially low ion temperature in some cases.
Key words: atomic data / ISM: abundances / ISM: atoms / ultraviolet: general / Sun: abundances
© European Southern Observatory (ESO), 1997