Seismic analysis of the second ionization region of helium in the Sun - I. Sensitivity study and methodology
Seismic analysis of the second ionization region of helium in the Sun - I. Sensitivity study and methodology
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太阳氦第二电离区的地震分析 - I. 敏感性研究和方法
DOI：
10.1111/j.1365-2966.2005.09246.x
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
M. Thompson
中科院分区：
文献类型：
--
作者：
M. Monteiro;M. Thompson
太阳中氦的二次电离区域是靠近太阳表面的一层窄层。电离引起绝热指数Γ1的局域变化，从而在p个模的频率上产生特征信号。通过采用Monteiro，Christensen-Dalsgaard和Thompson发展的方法，我们提出了一种通过研究振荡频率中的这种特征来确定该区域性质的方法。
利用太阳数据，我们说明了如何分离来自氦电离区的信号。使用每个太阳模型都使用了不同的物理-对流理论、状态方程和低温不透明度-我们确定了信号的特征如何依赖于对电离层结构起作用的各种物理过程。我们进一步讨论了如何使用该方法来测量包层中的太阳氦丰度，并限制影响太阳这一区域的物理因素。
文中给出了该方法的应用实例。它可能是为研究太阳结构和确定包层氦丰度而开发的其他反演方法的补充。
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.