Asteroseismic Modeling of Gravity Modes in Slowly Rotating A/F Stars with Radiative Levitation
Abstract
It has been known for several decades that transport of chemical elements is induced by the process of microscopic atomic diffusion. Yet the effect of atomic diffusion, including radiative levitation, has hardly been studied in the context of gravitymode pulsations of core hydrogen burning stars. In this paper we study the difference in the properties of such modes for models with and without atomic diffusion. We perform asteroseismic modeling of two slowly rotating A and Ftype pulsators, KIC 11145123 ( ${f}_{\mathrm{rot}}$ $\approx \,0.010\,{\mathrm{day}}^{1}$ ) and KIC 9751996 ( ${f}_{\mathrm{rot}}$ $\approx \,0.0696\,{\mathrm{day}}^{1}$ ), respectively, based on the periods of individual gravity modes. For both stars, we find models whose gmode periods are in very good agreement with the Kepler asteroseismic data, keeping in mind that the theoretical/numerical precision of presentday stellar evolution models is typically about two orders of magnitude lower than the measurement errors. Using the Akaike Information Criterion, we have made a comparison between our best models with and without diffusion and found very strong evidence for signatures of atomic diffusion in the pulsations of KIC 11145123. In the case of KIC 9751996 the models with atomic diffusion are not able to explain the data as well as the models without it. Furthermore, we compare the observed surface abundances with those predicted by the bestfitting models. The observed abundances are inconclusive for KIC 9751996, while those of KIC 11145123 from the literature can better be explained by a model with atomic diffusion.
 Publication:

The Astrophysical Journal
 Pub Date:
 May 2020
 DOI:
 10.3847/15384357/ab8d36
 arXiv:
 arXiv:2004.13037
 Bibcode:
 2020ApJ...895...51M
 Keywords:

 Asteroseismology;
 Stellar abundances;
 Stellar evolution;
 Stellar oscillations;
 Stellar processes;
 Stellar properties;
 73;
 1577;
 1599;
 1617;
 1623;
 1624;
 Astrophysics  Solar and Stellar Astrophysics
 EPrint:
 Accepted for publication in ApJ