Knowledge Bank

The two closely related electronic transitions of XeO near the oxygen auroral green line have been studied. The $21\Sigma +-11\Pi$ transition, which lies mostly to the red of the oxygen line (at 5577 {\AA}), is well resolved and shows only a small amount of predissociation in the lower state, although rotational predissociation is observed as the lower state rotational levels go over the top of the potential well. The vibrational numbering has been verified by measuring both $129Xe16O$ and $129Xe18O$. The potential functions for both the $21\Sigma +$ and $11\Pi$ states are given. The ground vibrational state bond distances are found to be $2.880\pm 0.010\backslash AA$ for the $21\Sigma +$state and $2.609\pm 0.010\backslash AA$ for the $11\Pi$ state. The $21\Sigma +-11\Sigma +$ transition which lies entirely to the blue of the oxygen line is severely predissociated although an interesting variation of line width with rotational quantum number is observed, With the aid of the $21\Sigma +-11\Pi$ analysis the rotational structure of the $21\Sigma +-11\Sigma +$ transition can be assigned and work is in progress to define the potential function for the lower $11\Sigma +$ state.