The {\gamma} Dor stars as revealed by Kepler : A key to reveal deep-layer rotation in A and F stars

TL;DR

This paper uses Kepler data to analyze { extgamma} Dor stars, revealing their potential to probe deep internal rotation and angular momentum transport in intermediate-mass stars, which is crucial for understanding stellar evolution.

Contribution

It presents the first seismic diagnostics for mid- to fast-rotating { extgamma} Dor stars using Kepler data, advancing the study of internal rotation in these stars.

Findings

Kepler data reveals regular frequency spectra in { extgamma} Dor stars.

Seismic diagnostics can probe internal rotation and angular momentum transport.

Potential to explore the rotation history of early stellar evolution.

Abstract

The {\gamma} Dor pulsating stars present high-order gravity modes, which make them important targets in the intermediate-and low-mass main-sequence region of the Hertzsprung-Russell diagram. Whilst we have only access to rotation in the envelope of the Sun, the g modes of {\gamma} Dor stars can in principle deliver us constraints on the inner layers. With the puzzling discovery of unexpectedly low rotation rates in the core of red giants, the {\gamma} Dor stars appear now as unique targets to explore internal angular momentum transport in the progenitors of red giants. Yet, the {\gamma} Dor pulsations remain hard to detect from the ground for their periods are close to 1 day. While the CoRoT space mission first revealed intriguing frequency spectra, the almost uninterrupted 4-year photometry from the Kepler mission eventually shed a new light on them. It revealed regularities in the spectra, expected to bear signature of physical processes, including rotation, in the shear layers close to the convective core. We present here the first results of our effort to derive exploitable seismic diagnosis for mid- to fast rotators among {\gamma} Dor stars. We confirm their potential to explore the rotation history of this early phase of stellar evolution.