ECLIPSE MAPPING OF THE ACCRETION DISK WIND IN THE CATACLYSMIC VARIABLE UX URSAE-MAJORIS

We present the results of an effort to model recent HST eclipse observ ations of the C IV 1550 Angstrom resonance line in the high-inclinatio n nova-like cataclysmic variable UX UMa. Assuming this line to be pred ominantly wind-formed, we are able to roughly reproduce the shapes and strengths of the observed line profiles (both away from and during ec lipse) within the framework of a simple kinematic model in which the o utflow is described as a rotating, biconical accretion disk wind. Our preferred model also matches most of the detailed behavior of differen t parts of the C IV line profile (blue wing, line center, and red wing ) as a function of orbital phase. The most important result of our mod eling is that it strongly suggests the presence of a high column (N-H similar to 10(23) cm(-2)), relatively dense (n(e) similar or equal to 4 x 10(12) cm(-3)), and only slowly outflowing (v(poloidal) much less than v(escape)) transition region between the disk photosphere and the fast-moving wind. We also find that the outflow from UX UMa is probab ly only moderately collimated (the outer opening angle of our preferre d model is theta(max) similar or equal to 65 degrees). Finally, the ro tational disturbance seen in the data is fitted reasonably well by our model, in which the rotational component of motion in the wind is fix ed by conserving the specific angular momentum of the outflowing mater ial. The implications of these results for dynamical models of disk-dr iven winds are discussed.