  Wind mass transfer in binary systems with AGB donor stars plays a fundamental
role in the formation of a variety of objects, including barium stars and CEMP
stars. We carry out a comprehensive set of SPH simulations of wind-losing AGB
stars in binaries, for a variety of binary mass ratios, orbital separations,
initial wind velocities and rotation rates of the donor star. The initial
parameters of the simulated systems are chosen to match the expected
progenitors of CEMP stars. We find that the strength of interaction between the
wind and the stars depends on both the wind-velocity-to-orbital-velocity ratio
($v_\infty/v_\mathrm{orb}$) and the binary mass ratio. Strong interaction
occurs for close systems and comparable mass ratios, and gives rise to a
complex morphology of the outflow and substantial angular-momentum loss, which
leads to a shrinking of the orbit. As the orbital separation increases and the
mass of the companion star decreases, the morphology of the outflow, as well as
the angular-momentum loss, become more similar to the spherically symmetric
wind case. We also explore the effects of tidal interaction and find that for
orbital separations up to 7-10 AU, depending on mass ratio, spin-orbit coupling
of the donor star occurs at some point during the AGB phase. If the initial
wind velocity is relatively low, we find that corotation of the donor star
results in a modified outflow morphology that resembles wind Roche-lobe
overflow. In this case the mass-accretion efficiency and angular-momentum loss
differ from those found for a non-rotating donor. Finally, we provide a
relation for both the mass-accretion efficiency and angular-momentum loss as a
function of $v_\infty/v_\mathrm{orb}$ and the binary mass ratio that can be
easily implemented in a population synthesis code to study populations of
barium stars, CEMP stars and other products of interaction in AGB binaries.

Solar and Stellar Astrophysics