Nonadiabatic nonradial p-mode frequencies of the standard solar model, with and without helium diffusion
Nonadiabatic nonradial p-mode frequencies of the standard solar model, with and without helium diffusion
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DOI：
10.1086/173735
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发表时间：
1994-02
期刊：
影响因子：
--
通讯作者：
D. Guenther
中科院分区：
文献类型：
--
作者：
D. Guenther
讨论了标准太阳模型和含氦扩散的太阳模型的非绝热频率。非绝热脉动计算包括描述辐射损失和增益的物理学。辐射增益和损耗分别用扩散近似和Eddington近似进行建模，前者只在光学厚区有效，后者在光学薄区和厚区都有效。计算的l小于等于1320模态的脉动频率与观测到的太阳光谱进行了比较。与严格绝热计算相比，p模频率的非绝热计算提高了模型与观测的一致性。当模型中加入氦扩散时，对对流区底部附近区域敏感的模态频率得到改善（即与观测值更接近），而对其他模态的一致性则变差。太阳频率间隔的周期性变化作为频率n的函数被提出作为太阳结构不连续的证据，可能位于对流区的底部附近。
The nonadiabatic frequencies of a standard solar model and a solar model that includes helium diffusion are discussed. The nonadiabatic pulsation calculation includes physics that describes the losses and gains due to radiation. Radiative gains and losses are modeled in both the diffusion approximation, which is only valid in optically thick regions, and the Eddington approximation, which is valid in both optically thin and thick regions. The calculated pulsation frequencies for modes with l less than or equal to 1320 are compared to the observed spectrum of the Sun. Compared to a strictly adiabatic calculation, the nonadiabatic calculation of p-mode frequencies improves the agreement between model and observation. When helium diffusion is included in the model the frequencies of the modes that are sensitive to regions near the base of the convection zone are improved (i.e., brought into closer agreement with observation), but the agreement is made worse for other modes. Cyclic variations in the frequency spacings of the Sun as a function of frequency of n are presented as evidence for a discontinuity in the structure of the Sun, possibly located near the base of the convection zone.