SPH modelling of wind-companion interactions in eccentric AGB binary systems

The late evolutionary stages of low- and intermediate-mass stars are characterised by mass loss through a dust-driven stellar wind. Recent observations reveal complex structures within these winds, that believed to be formed primarily via interaction with companion. How complexities arise, which in type systems, is still poorly understood. Particularly, there lack studies investigating the structure formation eccentric systems. We aim improve our understanding wind morphology AGB binary systems mechanism responsible for different small-scale global morphologies arise polytropic velocities. Using smoothed particle hydrodynamics (SPH) code Phantom, we generate nine high-resolution, 3D simulations an star solar-mass companion various velocity eccentricity combinations. models assume gas, no additional cooling. conclude high velocity, short results regular spiral morphology, flattened. In case lower stronger high-energy region bow-shock can shape into irregular if instabilities arise. High-eccentricity show complex, phase-dependent leading three dimensions. However, significant compresses matter equatorial density enhancement, irrespective eccentricity.