A Re-examination of Stellar Opacities and Implications for Solar Models

重新审视恒星的不透明度及其对太阳模型的影响

• 批准号: 0907763
• 负责人: Anil Pradhan
• 金额: $ 39.5万
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0907763&HistoricalAwards=false
• 关键词: Re; examination; Stellar; Opacities; Implications

AST-0907763PradhanThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Stellar opacity is the fundamental quantity in stellar models. In recent years an inexplicable solar abundances anomaly has emerged, between light element abundances derived spectroscopically and from the most sophisticated atmospheres models, on the one hand, and interior models consistent with extremely accurate helioseismological observations, on the other hand. An increase in opacity of 10-20% could perhaps reconcile the currently divergent models, and the primary aim of this project is to investigate the accuracy of the models and test this suggestion, focusing on a detailed quantitative re-assessment of opacities. The work entails more accurate and extensive atomic calculations, including relativistic effects, an improved equation of state in the "chemical picture", and high-resolution computation of monochromatic and mean opacities, and radiative accelerations. The new opacities codes will be interfaced with an electronic data server for efficient distribution.The calculation of opacities and radiative accelerations is a symbiotic exercise in atomic physics, plasma physics, and astrophysics. Although the results will be generally useful in many stellar studies, the impact will be much wider. Large-scale high-accuracy atomic data are useful in spectral analysis of nebulae, active galactic nuclei, supernovae, and other astronomical objects, and also very helpful in nuclear fusion plasma diagnostics, laser-atom interactions, and photoionization studies on synchrotron based light sources. Even more generally, these advanced methods in atomic physics cover important science from atmospheric research to energy technology.

AST-0907763 PRADHAN该奖项是根据2009年美国复苏和再投资法案(公法111-5)资助的。恒星不透明度是恒星模型中的基本量。近年来出现了一种莫名其妙的太阳丰度异常，一方面是从光谱和最复杂的大气模型得出的轻元素丰度，另一方面是与极其精确的日震观测相一致的内部模型。不透明度增加10%-20%可能会协调目前存在分歧的模型，该项目的主要目标是调查模型的准确性并测试这一建议，重点是对不透明度进行详细的定量重新评估。这项工作需要更准确和更广泛的原子计算，包括相对论效应，“化学图片”中改进的状态方程，以及单色和平均不透明度以及辐射加速的高分辨率计算。新的不透明度代码将与电子数据服务器接口，以实现有效的分配。不透明度和辐射加速的计算是原子物理、等离子体物理和天体物理中的一项共生练习。尽管这些结果将在许多恒星研究中普遍有用，但其影响将更加广泛。大尺度的高精度原子数据在星云、活动星系核、超新星和其他天文天体的光谱分析中是有用的，在核聚变等离子体诊断、激光-原子相互作用和同步辐射光源的光电离研究中也非常有用。更广泛地说，原子物理学中的这些先进方法涵盖了从大气研究到能源技术的重要科学。