Three-dimensional hydrodynamical simulations of mass transfer in binary systems by a free wind

TL;DR

This study uses 3D hydrodynamical simulations to investigate how stellar wind mass transfer occurs in binary systems, revealing how accretion efficiency depends on system mass ratios and wind properties.

Contribution

It provides new insights into wind mass transfer processes in wide binaries through detailed 3D simulations focusing on free wind scenarios.

Findings

Accretion efficiency increases with mass ratio.

Efficiency varies from 0.1% to 8% for different mass ratios.

Mass outflow geometries depend on system parameters.

Abstract

A large fraction of stars in binary systems are expected to undergo mass and angular momentum exchange at some point in their evolution, which can drastically alter the chemical and dynamical properties and fates of the systems. Interaction by stellar wind is an important process in wide binaries. However, the details of wind mass transfer are still not well understood. We perform three-dimensional hydrodynamical simulations of wind mass transfer in binary systems to explore mass accretion efficiencies and geometries of mass outflows, for a range of mass ratios from 0.05 to 1.0. In particular, we focus on the case of a free wind, in which some physical mechanism accelerates the expelled wind material balancing the gravity of the mass-losing star with the wind velocity comparable to the orbital velocity of the system. We find that the mass accretion efficiency and accreted specific angular momentum increase with the mass ratio of the system. For an adiabatic wind, we obtain that the accretion efficiency onto the secondary star varies from about 0.1% to 8% for mass ratios between 0.05 and 1.0.