Monteiro, M.J.P.F.G. and Thompson, M.J. (2005) Seismic analysis of the second ionization region of helium in the Sun - I. Sensitivity study and methodology. Monthly Notices of the Royal Astronomical Society, 361 (4). pp. 1187-1196. ISSN 0035-8711
Abstract
The region of the second ionization of helium in the Sun is a narrow layer near the surface. Ionization induces a local change in the adiabatic exponent Γ1, which produces a characteristic signature in the frequencies of p modes. By adapting the method developed by Monteiro, Christensen-Dalsgaard & Thompson, we propose a methodology for determining the properties of this region by studying such a signature in the frequencies of oscillation. Using solar data we illustrate how the signal from the helium ionization zone can be isolated. Using solar models which each use different physics — the theory of convection, equation of state and low-temperature opacities — we establish how the characteristics of the signal depend on the various physical processes contributing to the structure in the ionization layer. We further discuss how the method can be used to measure the solar helium abundance in the envelope and to constrain the physics affecting this region of the Sun. The potential usefulness of the method we propose is shown. It may complement other inversion methods developed to study the solar structure and to determine the envelope helium abundance.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2005 RAS. Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | equation of state; Sun : abundances; Sun : helioseismology; Sun : interior; Sun : oscillations; stars : abundances |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Mathematics and Statistics (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 15 Apr 2019 11:26 |
Last Modified: | 18 Apr 2019 04:56 |
Status: | Published |
Publisher: | Oxford University Press for Royal Astronomical Society |
Refereed: | Yes |
Identification Number: | 10.1111/j.1365-2966.2005.09246.x |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:144862 |