Inference from adiabatic analysis of solar-like oscillations in Red giants

TL;DR

This paper analyzes adiabatic oscillation frequencies in red giants, showing how their properties reveal internal structures and evolutionary stages, supported by models and Kepler data.

Contribution

It provides a detailed overview of adiabatic frequency properties in red giants across different stages, linking seismic diagnostics to stellar evolution.

Findings

Dipole mode properties diagnose evolutionary stage

Frequency separations depend on stellar parameters

Theoretical predictions align with Kepler observations

Abstract

The clear detection with CoRoT and KEPLER of radial and non-radial solar-like oscillations in many red giants paves the way to seismic inferences on the structure of such stars. We present an overview of the properties of the adiabatic frequencies and frequency separations of radial and non-radial oscillation modes, highlighting how their detection allows a deeper insight into the properties of the internal structure of red giants. In our study we consider models of red giants in different evolutionary stages, as well as of different masses and chemical composition. We describe how the large and small separations computed with radial modes and with non-radial modes mostly trapped in the envelope depend on the stellar global parameters and evolutionary state, and we compare our theoretical predictions and first KEPLER data.Finally, we find that the properties of dipole modes constitute a promising seismic diagnostic of the evolutionary state of red-giant stars.