Determination of temperature and chemical composition profiles in the solar interior from seismic models

Abstract

The primary inversion of the solar oscillation frequencies coupled with the equations of thermal equilibrium and input physics enable us to infer the temperature and hydrogen abundance profiles inside the Sun. The inferred hydrogen abundance profile is smoother than that in a solar model with conventional treatment of diffusion, in the region just beneath the solar convection zone (r≳0.68 RΘ ). Such a mixing process could account for the observed low lithium abundance in the solar envelope. It is also possible to constrain the nuclear reaction rates using the inferred temperature and hydrogen abundance profiles. The helioseismically estimated cross-section for pp nuclear reaction turns out to be (4.15±0.25)*E^-25 MeV barns, where the error estimates include those from opacities arising from up to 50% uncertainty in heavy element abundance Z.