论文标题
研究RGB恒星的表面校正关系
Investigating surface correction relations for RGB stars
论文作者
论文摘要
最先进的恒星结构和进化代码无法充分描述湍流对流。对于具有对流信封的恒星,例如红色巨人,这会导致表面层的不完整描述。结果,预测的恒星振荡频率被系统的误差(即所谓的表面效应)困扰。已经提出了不同的经验和理论上动机的纠正关系来解决这个问题。在本文中,我们比较了红色巨型分支恒星这些表面校正关系的性能。为此,我们将不同的表面校正关系应用于黯然失色的二进制和开放簇的星号分析中。根据先前对主要序列恒星的研究,我们发现使用不同的表面校正关系偏向于派生的全球恒星特性,包括恒星年龄,质量和距离估计值。我们进一步表明,不同的关系导致两个不同的开放群集遇到相同的系统误差。我们的结果总体上不愿使用依赖参考星来校准游离参数的表面校正关系的使用。由于结果表现出了系统的偏见,因此使用适当的表面校正关系对于任何对红色巨人的小型震中分析至关重要。在解决涉及银河系的化学动力发展的问题时,红色巨人的准确质量,年龄和距离估计是基本的。这样,我们的结果也对诸如银河考古学等领域具有影响,这些田地借鉴了恒星物理学的发现。
State-of-the-art stellar structure and evolution codes fail to adequately describe turbulent convection. For stars with convective envelopes, such as red giants, this leads to an incomplete depiction of the surface layers. As a result, the predicted stellar oscillation frequencies are haunted by systematic errors, the so-called surface effect. Different empirically and theoretically motivated correction relations have been proposed to deal with this issue. In this paper, we compare the performance of these surface correction relations for red giant branch stars. For this purpose, we apply the different surface correction relations in asteroseismic analyses of eclipsing binaries and open clusters. In accordance with previous studies of main-sequence stars, we find that the use of different surface correction relations biases the derived global stellar properties, including stellar age, mass, and distance estimates. We furthermore demonstrate that the different relations lead to the same systematic errors for two different open clusters. Our results overall discourage from the use of surface correction relations that rely on reference stars to calibrate free parameters. Due to the demonstrated systematic biasing of the results, the use of appropriate surface correction relations is imperative to any asteroseismic analysis of red giants. Accurate mass, age, and distance estimates for red giants are fundamental when addressing questions that deal with the chemo-dynamical evolution of the Milky Way galaxy. In this way, our results also have implications for fields, such as galactic archaeology, that draw on findings from stellar physics.