2002ApJS..138..305S

Laboratory measurements of line oscillator strengths in the ``intersystem'' bands of carbon monoxide currently provide an incomplete data set for the interpretation of astronomical observations in the vacuum ultraviolet region. We report line f-values in two intersystem bands, d³Δ(v=7)-X¹Σ⁺(v=0) at 146.4 nm and e³Σ^–(4)-X(0) at 147.1 nm, from photoabsorption spectra recorded with an instrumental resolution of 7.6x10^–4 nm (resolving power ∼190,000). The high-resolution measurements (1) minimize line saturation effects in the determination of f-values and (2) allow for the direct experimental determination of the f-values of low-J lines that contribute to interstellar absorption features. We compare our measured line f-values with those generated from the intersystem band model of Rostas and coworkers. We find the predictions of relative line f-values within each band to be in agreement with the measurements, but there are discrepancies in the absolute scale. Based on this comparison, we present recommended f-values for low-J rotational lines within each band.