Resonance Line Profile Calculations Based on Hydrodynamical Models of Cataclysmic Variable Winds

We present synthetic line profiles as predicted by the models of 2-D line-driven disk winds due to Proga, Stone & Drew. We compare the model lineprofiles with HST observations of the cataclysmic variable IX Vel. The modelwind consists of a slow outflow that is bounded on the polar side by a faststream. We find that these two components of the wind produce distinct spectralfeatures. The fast stream produces profiles which show features consistent withobservations. These include the appearance of the P-Cygni shape for a range ofinclinations, the location of the maximum depth of the absorption component atvelocities less than the terminal velocity, and the transition from absorptionto emission with increasing inclination. However the model profiles have toolittle absorption or emission equivalent width. This quantitative differencebetween our models and observations is not a surprise because the line-drivenwind models predict a mass loss rate that is lower than the rate required bythe observations. We note that the model profiles exhibit a double-humpedstructure near the line center which is not echoed in observations. We identifythis structure with a non-negligible redshifted absorption which is formed inthe slow component of the wind where the rotational velocity dominates overexpansion velocity. We conclude that the next generation of disk wind models,developed for application to CVs, needs to yield stronger wind driving out tolarger disk radii than do the present models.Comment: LaTeX, 19 pages, to appear in Ap