Impact of rotation on the evolution of convective vortices in collapsing stars

TL;DR

This study investigates how rotation influences the evolution of convective vortices during stellar collapse, revealing that rotation mainly causes angular deformation and vortex amplification, with minimal effects on radial velocities and acoustic emissions.

Contribution

The paper introduces a linear hydrodynamics model to analyze the effects of rotation on vortex evolution in collapsing stars, highlighting the roles of infall acceleration and rotation speed-up.

Findings

Vortices are radially stretched, limiting their velocities.

Rotation causes angular deformation and amplifies non-radial velocities.

Acoustic wave emission is largely unaffected by rotation.

Abstract

We study the impact of rotation on the hydrodynamic evolution of convective vortices during stellar collapse. Using linear hydrodynamics equations, we study the evolution of the vortices from their initial radii in convective shells down to smaller radii where they are expected to encounter the supernova shock. We find that the evolution of vortices is mainly governed by two effects: the acceleration of infall and the accompanying speed up of rotation. The former effect leads to the radial stretching of vortices, which limits the vortex velocities. The latter effect leads to the angular deformation of vortices in the direction of rotation, amplifying their non-radial velocity. We show that the radial velocities of the vortices are not significantly affected by rotation. We study acoustic wave emission and find that it is not sensitive to rotation. Finally, we analyze the impact of the corotation point and find that it has a small impact on the overall acoustic wave emission.