Stellar Wind Accretion and Raman O VI Spectroscopy of the Symbiotic Star AG Draconis

Raman scattered O VI features at 6825 Å and 7082 Å found in symbiotic stars are important spectroscopic tools to probe the mass transfer process. Adopting a Monte Carlo approach, we perform a profile analysis of Raman O VI features of the yellow SySt AG Draconis and make a comparison with the spectrum obtained with CFHT. It is assumed that the accretion flow is convergent on the entering side with enhanced O VI emission and the flux ratio F(1032)/F(1038)∼1, whereas on the opposite side the flow is divergent with low O VI emission and F(1032/F(1038)∼2. Our best fit to the spectrum is obtained from our model with a mass-loss rate of the giant ∼4 × 10^-7 M_⊙ yr^-1. A slight red wing excess in the spectrum suggests the presence of bipolar neutral components receding in the directions perpendicular to the binary orbital plane with a speed ∼70km s^-1