Asteroseismic analysis of red giants in eclipsing binaries using two methods: implications for scaling relations and chemical composition

ABSTRACT The study of solar-like oscillating red giants in eclipsing binaries (EBs) provides a unique opportunity to advance stellar astrophysics by combining dynamical mass and radius measurements with asteroseismic constraints. EBs provide precise fundamental parameters (e.g. mass, radius, and luminosity) independent of distance, while solar-like oscillations probe stellar interiors and enable tests of asteroseismic scaling relations used to determine stellar masses and radii. We apply two different methods to estimate the initial chemical composition of the systems. In Method I, the initial helium abundance ($Y_0$) is treated as the free parameter, whereas in Method II the free parameter is the initial metallicity ($Z_0$), assuming a relation between $Y_0$ and $Z_0$. We construct interior models individually for the components of 11 EBs and obtain coeval solutions for eight systems. The ages and chemical compositions derived from the two methods are generally consistent with each other. Our results provide important clues about the chemical evolution of a part of the Galactic disk. Moreover, using the parameters obtained for two oscillating stars, Tek Ayak (KIC 8410637) and KIC 9970396, instead of solar reference values in the scaling relations yields masses and radii that are in much better agreement with the dynamical solutions without requiring additional corrections.