Angular momentum transport by internal gravity waves

IV. Wave generation by surface convection zone, from the pre-main sequence to the early-AGB in intermediate mass stars

¹ Département de Physique, Université de Montréal, Montréal PQ H3C 3J7, Canada e-mail: talon@astro.umontreal.ca
² Geneva Observatory, University of Geneva, ch. des Maillettes 51, 1290 Sauverny, Switzerland e-mail: Corinne.Charbonnel@obs.unige.ch
³ Laboratoire d'Astrophysique de Toulouse et Tarbes, CNRS UMR 5572, OMP, Université Paul Sabatier 3, 14 Av. E. Belin, 31400 Toulouse, France

Received: 5 September 2007
Accepted: 26 December 2007

Abstract

Context. This is the fourth in a series of papers that deal with angular momentum transport by internal gravity waves in stellar interiors.

Aims. Here, we want to examine the potential role of waves in other evolutionary phases than the main sequence.

Methods. We study the evolution of a Population I model from the pre-main sequence to the early-AGB phase and examine whether waves can lead to angular momentum redistribution and/or element diffusion at the external convection zone boundary.

Results. We find that, although waves produced by the surface convection zone can be ignored safely for such a star during the main sequence, it is not the case for later evolutionary stages. In particular, angular momentum transport by internal waves could be quite important at the end of the sub-giant branch and during the early-AGB phase. Wave-induced mixing of chemicals is expected during the early-AGB phase.