Seismology of the solar envelope: sound-speed gradient in the convection zone and its diagnosis of the equation of state |
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| Authors: | V A Baturin W Däppen D O Gough S V Vorontsov |
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| Institution: | Sternberg Astronomical Institute, Universitetsky Prospect 13, Moscow 119899, Russia;Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089-1342, USA;Institute of Astronomy, Madingley Road, Cambridge CB3 0HA;Department of Applied Mathematics and Theoretical Physics, Silver Street, Cambridge CB3 9EW;Astronomy Unit, Queen Mary and Westfield College, Mile End Road, London E1 4NS;Institute of Physics of the Earth, B. Gruzinskaya 10, Moscow 123810, Russia |
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| Abstract: | We report the results of an asymptotic inversion of solar oscillation data for the gradient of the sound speed in the convection zone. This gradient reveals details of the non-ideal Coulomb interactions between particles, including pressure ionization. A simplified physical model is used to track down the effect of various physical assumptions in the sound-speed derivative. The model contains a calibration for the size of the H and He atoms and the He+ ion. We find that, for the pressure‐ionization regions of hydrogen and helium, such a model matches the data better than any of the currently available parameter-free theories. |
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| Keywords: | atomic data equation of state Sun: abundances Sun: oscillations |
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