TRANSITION-PROBABILITIES IN O-III

Transition data has been computed in the MCHF + Breit-Pauli approximation for a number of the low lying triplets in O III- Special attention was given to the 2p3p3P-2p3d3P transition which is a primary cascade for the Bowen fluorescence mechanism in O III. The relativistic, largely spin-orbit, effect on the intensity ratio of primary decays was found to be as large as 50%, whereas the effect on secondary cascades was less than 30%. Agreement with astrophysically observed intensity ratios is excellent. There also is good agreement between the present liftimes and the beam-foil mean lifetimes obtained by Pinnington et al., though for 2p3p3D and 3S the theoretical lifetimes are considerably shorter.