Impact of internal gravity waves on the rotation profile inside pre-main sequence low-mass stars

TL;DR

This study models how internal gravity waves and other processes influence the internal rotation and surface velocity evolution of low-mass pre-main sequence stars, revealing that IGW significantly alter their internal rotation profiles.

Contribution

It introduces a comprehensive stellar evolution model that incorporates IGW, meridional circulation, shear turbulence, and contraction to study angular momentum transport in PMS stars.

Findings

IGW are efficiently generated by the convective envelope.

IGW slow down the stellar core early in PMS evolution.

In stars >1.6Msun, core-generated IGW also affect angular momentum near ZAMS.

Abstract

We study the impact of internal gravity waves (IGW), meridional circulation, shear turbulence, and stellar contraction on the internal rotation profile and surface velocity evolution of solar metallicity low-mass pre-main sequence stars. We compute a grid of rotating stellar evolution models with masses between 0.6 and 2.0Msun taking these processes into account for the transport of angular momentum, as soon as the radiative core appears and assuming no more disk-locking from that moment on.IGW generation along the PMS is computed taking Reynolds-stress and buoyancy into account in the bulk of the stellar convective envelope and convective core (when present). Redistribution of angular momentum within the radiative layers accounts for damping of prograde and retrograde IGW by thermal diffusivity and viscosity in corotation resonance. Over the whole mass range considered, IGW are found to be efficiently generated by the convective envelope and to slow down the stellar core early on the PMS. In stars more massive than ~ 1.6Msun, IGW produced by the convective core also contribute to angular momentum redistribution close to the ZAMS. Overall, IGW are found to significantly change the internal rotation profile of PMS low-mass stars.