ON THE SYNTHESIS OF RESONANCE LINES IN DYNAMICAL MODELS OF STRUCTUREDHOT-STAR WINDS

We examine basic issues involved in synthesizing resonance-line profil es from 1-D, dynamical models of highly structured hot-star winds. Alt hough these models exhibit extensive variations in density as well as velocity, the density scale length is still typically much greater tha n the Sobolev length. The line transfer is thus treated using a Sobole v approach, as generalized by Rybicki and Hummer (1978) to take proper account of the multiple Sobolev resonances arising from the nonmonoto nic velocity held. The resulting reduced-lambda-matrix equation descri bing nonlocal coupling of the source function is solved by iteration, and line profiles are then derived from formal solution integration us ing this source function. Two more approximate methods that instead us e either a stationary or a structured, local source function yield qua litatively similar line-profiles, but are found to violate photon cons ervation by 10% or more. The full results suggest that such models may indeed be able to reproduce naturally some of the qualitative propert ies long noted in observed UV line profiles, such as discrete absorpti on components in unsaturated lines, or the blue-edge variability in sa turated lines. However, these particular models do not yet produce the black absorption troughs commonly observed in saturated lines, and it seems that this and other important discrepancies (e.g., in accelerat ion time scale of absorption components) may require development of mo re complete models that include rotation and other 2-D and/or 3-D effe cts.