Impacts of radiative accelerations on solar-like oscillating main-sequence stars
Impacts of radiative accelerations on solar-like oscillating main-sequence stars
复制标题
辐射加速度对类太阳振荡主序星的影响
DOI：
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发表时间：
2018
影响因子：
6.5
通讯作者：
B. Pichon
中科院分区：
文献类型：
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作者：
M. Deal;G. Alecian;Y. Lebreton;M. Goupil;J. Marques;F. Leblanc;P. Morel;B. Pichon
上下文。化学元素传输过程是精确恒星模型所需的关键物理过程之一。重力沉降引起的原子扩散通常被考虑在内，这对于日震研究是必不可少的。另一方面，辐射加速很少被考虑，对各种化学元素的作用不同，并且在一些恒星质量区域可以强烈地抵消引力。由此产生的丰度分布的变化可能会对恒星的结构产生重大影响。
目标。这项研究的目的是确定辐射加速是否影响星震空间任务观测到的类太阳振荡主序星的结构。
方法：研究方法。用单值参数法实现了CESTAM程序中C、N、O、Ne、Na、Mg、Al、Si、S、Ca和Fe的辐射加速计算。我们建立并比较了几种恒星模型的网格，包括引力沉降、有辐射加速的和没有辐射加速的。我们考虑了质量在[0.9，1.5]M⊙范围内和太阳值附近的金属丰度的三个值。对于每个金属丰度，我们确定了由于辐射加速导致的模型之间的差异超过开普勒遗产样本的全球地震参数的不确定性或柏拉图观测的预期的质量范围。
结果。我们发现，在太阳金属丰度下，当恒星质量大于1.1M⊙时，辐射加速效应是不可忽略的。对于我们网格中质量更大的恒星，由于它们包含在模型中而导致的年龄差异可以达到9%。我们估计，根据地震数据的精度，其建模需要辐射加速的柏拉图核心计划恒星的百分比在33%到58%之间。
结论。我们的结论是，在提供(或将提供)高质量地震数据的开普勒、TESS和柏拉图任务的背景下，当适当地推断类太阳振荡器的性质时，辐射加速可以产生显著的影响。这对于年龄推断尤其重要。然而，每一颗恒星的净效应是原子扩散(包括辐射加速)和其他内部传输过程竞争的结果。例如，旋转诱导的输运过程被认为可以减少原子扩散的影响。这一点将在即将发表的配套论文中进行研究。
Context. Chemical element transport processes are among the crucial physical processes needed for precise stellar modelling. Atomic diffusion by gravitational settling is usually taken into account, and is essential for helioseismic studies. On the other hand, radiative accelerations are rarely accounted for, act differently on the various chemical elements, and can strongly counteract gravity in some stellar mass domains. The resulting variations in the abundance profiles may significantly affect the structure of the star.
Aims. The aim of this study is to determine whether radiative accelerations impact the structure of solar-like oscillating main-sequence stars observed by asteroseismic space missions.
Methods. We implemented the calculation of radiative accelerations operating on C, N, O, Ne, Na, Mg, Al, Si, S, Ca, and Fe in the CESTAM code using the single-valued parameter method. We built and compared several grids of stellar models including gravitational settling, some with and others without radiative accelerations. We considered masses in the range [0.9, 1.5] M⊙ and three values of the metallicity around the solar value. For each metallicity we determined the mass range where differences between models due to radiative accelerations exceed the uncertainties of global seismic parameters of the Kepler Legacy sample or expected for PLATO observations.
Results. We found that radiative accelerations may not be neglected for stellar masses higher than 1.1 M⊙ at solar metallicity. The difference in age due to their inclusion in models can reach 9% for the more massive stars of our grids. We estimated that the percentage of the PLATO core program stars whose modelling would require radiative accelerations ranges between 33% and 58% depending on the precision of the seismic data.
Conclusions. We conclude that in the context of Kepler, TESS, and PLATO missions which provide (or will provide) high-quality seismic data, radiative accelerations can have a significant effect when properly inferring the properties of solar-like oscillators. This is particularly important for age inferences. However, the net effect for each individual star results from the competition between atomic diffusion including radiative accelerations and other internal transport processes. Rotationally induced transport processes for instance are believed to reduce the effects of atomic diffusion. This will be investigated in a forthcoming companion paper.
影响因子：
4.9
作者：
Aguirre, Victor Silva;Lund, Mikkel N.;Rendle, Ben
通讯作者：
Rendle, Ben