Laboratory transition probabilities for Gd II

The lifetimes are combined with branching fractions measured using Fourier transform spectrometry to determine transition probabilities for 611 lines of Gd II. This work is the largest-scale laboratory study to date of GdII transition probabilities and the first using a high-performance Fourier transform spectrometer.

This improved data set has been used to determine a new solar photospheric Gd abundance, log{epsilon}=1.11+/-0.03. Revised Gd abundances have also been derived for the r-process-rich metal-poor giant stars CS 22892-052, BD +17 3248, and HD 115444. The resulting Gd/Eu abundance ratios are in very good agreement with the solar system r-process ratio.