Evolutionary influences on the structure of red-giant acoustic oscillation spectra from 600d of Kepler observations

Abstract

Context: The Kepler space mission is reaching continuous observing times long enough to start studying the fine structure of the observed p-mode spectra. Aims: In this paper, we aim to study the signature of stellar evolution on the radial and p-dominated l=2 modes in an ensemble of red giants that show solar-type oscillations. Results: We find that the phase shift of the central radial mode (eps_c) is significantly different for red giants at a given large frequency separation (Dnu_c) but which burn only H in a shell (RGB) than those that have already ignited core He burning. Even though not directly probing the stellar core the pair of local seismic observables (Dnu_c, eps_c) can be used as an evolutionary stage discriminator that turned out to be as reliable as the period spacing of the mixed dipole modes. We find a tight correlation between eps_c and Dnu_c for RGB stars and no indication that eps_c depends on other properties of these stars. It appears that the difference in eps_c between the two populations becomes if we use an average of several radial orders, instead of a local, i.e. only around the central radial mode, Dnu to determine the phase shift. This indicates that the information on the evolutionary stage is encoded locally, in the shape of the radial mode sequence. This shape turns out to be approximately symmetric around the central radial mode for RGB stars but asymmetric for core He burning stars. We computed radial modes for a sequence of RG models and find them to qualitatively confirm our findings. We also find that, at least in our models, the local Dnu is an at least as good and mostly better proxy for both the asymptotic spacing and the large separation scaled from the model density than the average Dnu. Finally, we investigate the signature of the evolutionary stage on the small frequency separation and quantify the mass dependency of this seismic parameter.

12 pages, 9 figures, accepted for publication in A&A

References in corpus (15)

• Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars
• Fast core rotation in red-giant stars revealed by gravity-dominated mixed modes
• Testing Scaling Relations for Solar-Like Oscillations from the Main Sequence to Red Giants using Kepler Data
• Asteroseismology of old open clusters with Kepler: direct estimate of the integrated RGB mass loss in NGC6791 and NGC6819
• Calculating asteroseismic diagrams for solar-like oscillations
• Probing the core structure and evolution of red giants using gravity-dominated mixed modes observed with Kepler
• Characterization of the power excess of solar-like oscillations in red giants with Kepler
• YREC: The Yale Rotating Stellar Evolution Code
• Mixed modes in red-giant stars observed with CoRoT
• Granulation in Red Giants: observations by the Kepler mission and 3D convection simulations
• An asteroseismic signature of helium ionization
• Asteroseismic diagrams from a survey of solar-like oscillations with Kepler
• Nonradial p-modes in the G9.5 giant epsilon Oph? Pulsation model fits to MOST photometry
• Toward a New Kind of Asteroseismic Grid Fitting
• Frequency dependence of the large frequency separation of solar-like oscillators: Influence of the Helium second-ionization zone

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