Oscillator Strengths And Predissociation Rates For W−x Bands And The 4p5p Complex In 13c16o And 12c18o

We are conducting experiments on the DESIRS beam-line at the SOLEIL Synchrotron to acquire the necessary data on oscillator strengths and predissociation rates for modeling CO photochemistry in astronomical environments. A VUV Fourier Transform Spectrometer provides a resolving power of about 350,000, allowing us to discern individual lines in electronic transitions. Here we focus on results obtained from absorption spectra of $^{13}$C$^{16}$O and $^{12}$C$^{18}$O for the $W~^1\Pi~-~X~^1\Sigma^+$ bands with $v^{\prime}=0-3$ and $v^{\prime\prime}=0$ and the four overlapping bands (three resolved and one diffuse) observed between 92.97 and 93.35 nm. The three resolved bands are transitions to the upper levels 4p$\pi$(2), 5p$\pi$(0), and 5p$\sigma$(0) of the 4p(2) and 5p(0) complexes, and the diffuse band is associated with a non Rydberg level I $^1\Pi$; weak features in $^{13}$C$^{16}$O are likely associated with absorption to the 4p$\sigma$(2) and II $^1\Pi$ levels. Several perturbations are also revealed in the high-resolution spectra. We compare our results with earlier determinations for these isotopologues of CO, as well as our SOLEIL measurements on $^{12}$C$^{16}$O