Accretion disks in interacting binaries: Simulations of the stream-disk impact

We investigate the impact between the gas stream from the inner Lagrangian point and the accretion disk in interacting binaries using three-dimensional smoothed particle hydrodynamics simulations. We find that a significant fraction of the stream material can ricochet off the disk edge and overflow toward smaller radii and that this generates pronounced nonaxisymmetric structure in the absorption column toward the central object. We discuss the implications of our results for observations and time-dependent models of low-mass X-ray binaries, cataclysmic variables, and supersoft X-ray sources.