Empirical verification of the FeII oscillator strengths in the FUSE bandpass

We report empirical determinations of atomic oscillator strengths, or f-val ues, for 11 ground-state transitions of Fe 11 in the wavelength range 1050 less than or similar to lambda less than or similar to 1150 Angstrom. We us e ultraviolet absorption-line observations of interstellar material toward stars in the Galaxy and the Magellanic Clouds taken with Copernicus, the Go ddard High Resolution Spectrograph on board the Hubble Space Telescope, and the Ear-Ultraviolet Spectroscopic Explorer. We derive absolute oscillator strengths by a combination of the apparent optical depth, component-fitting , and curve-of-growth fitting techniques. Our derived oscillator strengths are generally in excellent agreement with recent theoretical calculations b y Raassen & Uylings using the orthogonal operator technique. However, we id entify three of the 11 transitions studied here whosef-values seem to be in compatible with these calculations by as much as a factor of 2. We suggest revisions to these f-values based on our analysis.