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A&A Supplement series, Vol. 122, April I 1997, 1-10

Received May 13; accepted July 2, 1996

Absolute transition probabilities for the atex2html_wrap_inline759D tex2html_wrap_inline761 ytex2html_wrap_inline763Ptex2html_wrap_inline765 multiplet (#8) of Fe II

K.L. Mullman - M. Sakai - J.E. Lawler

Send offprint request: K.L. Mullman
Department of Physics, University of Wisconsin-Madison, Madison, WI 53706, U.S.A.


We report the first laboratory measurement of absorption oscillator strengths (f-values) for 6 VUV (tex2html_wrap_inline771) transitions of the tex2html_wrap_inline773 multiplet (#8) in Fe II. We have also reconfirmed a recent measurement of the f-value of the Fe II resonance line at tex2html_wrap_inline777. These measurements are made with the high sensitivity absorption experiment at the University of Wisconsin-Madison. Measurements are also made on UV (tex2html_wrap_inline779) lines in Fe II with accurately known f-values in order to construct a reliable curve of growth for the experiment. Diffusive cooling of tex2html_wrap_inline783 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.

keywords: atomic data -- ISM: abundances -- ISM: atoms -- ultraviolet: general -- Sun: abundances

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