Simulating the Onset of Grazing Envelope Evolution of Binary Stars

TL;DR

This paper presents the first 3D gas-dynamical simulations of the grazing envelope evolution in binary stars, focusing on jet interactions and envelope ejection mechanisms at the onset of this phase.

Contribution

It introduces the first 3D simulations of GEE, demonstrating how jets influence envelope ejection and bubble formation during initial stages.

Findings

Jets inflate hot low-density bubbles.

Jets interact with previously ejected gas.

Envelope outskirts are effectively ejected by jets.

Abstract

We present the first three-dimensional gas-dynamical simulations of the grazing envelope evolution (GEE) of stars, with the goal of exploring the basic flow properties and the role of jets at the onset of the GEE. In the simulated runs, a secondary main-sequence star grazes the envelope of the primary asymptotic giant branch (AGB) star. The orbit is circular at the radius of the AGB primary star on its equator. We inject two opposite jets perpendicular to the equatorial plane from the location of the secondary star, and follow the evolution for several orbital periods. We explore the flow pattern by which the jets eject the outskirts of the AGB envelope. After one orbit the jets start to interact with gas ejected in previous orbits and inflate hot low-density bubbles.