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D. C. Morton (National Research Council, Herzberg Institute of Astrophysics)
The determination of element abundances from astronomical spectra depends directly on reliable transition probabilities. Many are now available from modern experimental methods, particularly lifetimes by selective laser excitation and branching fractions from accurately calibrated sources. Nevertheless, laboratory measurements are insufficient to meet all the needs of astrophysicists, so we must consider theoretical results as well.
Fortunately, several sophisticated sets of calculations with hundreds of configurations and relativistic corrections are now accessible in the literature or on web sites for many species. Some are ab initio calculations that predict the transition energies within a few percent of the measured values. Other approaches use the laboratory energies to obtain improved wavefunctions.
This talk will compare experimental and calculated transition probabilities from various authors to identify the most reliable sources and indicate where new data would be useful.
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Bulletin of the American Astronomical Society, 37 #2
© 2005. The American Astronomical Soceity.