Atomic Physics of Raman Scattered He IIλ4332

Raman scattering of far UV photons with atomic hydrogen is important in studying the mass loss and accretion processes in many symbiotic stars. We present basic atomic physical properties for the inelastic scattering of He II 949 with a hydrogen atom, which results in Raman scattered He II 4332 blueward of H gamma. At line center of He II 949, the total scattering cross section is computed to be σ _tot = 2.5 × 10^-22 cm² and the branching ratio into the level 2s is 0.12. It is proposed that comparisons of broad Balmer wings and Raman scattered He II features may provide an important diagnostic of far UV continuum around H I Lyman series.