Simulating Dense Gas in Active Galactic Nuclei, Tidal Disruption Events, and Supernovae

第一部分天文学是一门观测科学，而不是实验科学。 我们无法到达一颗星星并直接测量它的温度、密度或它如何产生能量。 相反，我们通过仔细研究不同颜色的光来发现这些东西。 原子和分子之间复杂的相互作用产生光。 PI正在开发一个大型计算机程序Cloudy来预测这一点。 Cloudy解决了量子力学和相对论的复杂方程。 天文学家使用Cloudy来模拟遥远的星星或星系中发生的事情，并预测发出的光。 这与通过望远镜看到的情况进行了比较。 这种比较使我们能够理解正在发生的事情。 Cloudy是免费提供的，是天文学中使用最广泛的代码之一。 他们组织国际研讨会，展示如何将Cloudy应用于研究项目。 Co-PI是西班牙人，将访问当地拥有大量西班牙裔人口的K-12学校。 他做西班牙语演讲和演讲。 西班牙裔学生和他们的家人参观大学的天文学讲座和观看与麦克亚当学生天文台。第2部分天文学是一个观察，而不是实验，科学。 我们无法直接测量星星或星系的温度、密度或能量来源。 我们通过定量光谱学发现这些东西，仔细研究观察到的光谱。 天文学的来源通常是远离平衡的。 它们的光谱取决于许多热、等离子体、化学和凝聚态过程。 分析解决方案是不可能的。 代码Cloudy在数值上解决了所有这些问题，以预测频谱。 这些预测与观测结果相比较，可以推断出星星或星系的性质. Cloudy是天体物理学中使用最广泛的理论代码之一，每年有300多篇论文引用它的文档。Cloudy长期以来一直使用现有的计算机和原子数据解决这些问题。 随着计算机变得更强大，原子数据变得更准确，模拟可以得到改进。 我们正在开发技术，以改善黑洞或爆炸恒星附近发现的致密气体的建模。 对"里德伯能级"（电子围绕离子的高激发轨道）的全面处理是关键的改进。 由于Cloudy广泛的社区使用，这项工作的影响将远远超出本项目。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Part 1Astronomy is an observational, not experimental, science. We cannot go to a star and directly measure its temperature, density, or how it makes energy. Rather, we discover these things by careful study of their light at different colors. Complex interactions between atoms and molecules produce light. The PIs are developing a large computer program, Cloudy, to predict this. Cloudy solves the complex equations of quantum mechanics and relativity. Astronomers use Cloudy to simulate what is happening in a distant star or galaxy and predict the emitted light. This is compared with what is seen through telescopes. This comparison makes it possible to understand what is happening. Cloudy is freely available and is among the more widely used codes in astronomy.The PIs will do two types of broader impact. They organize international workshops showing how to apply Cloudy to research projects. The Co-PI, a native of Spain, will visit local K-12 schools with large Hispanic populations. He does Spanish language talks and presentations. Hispanic students and their families visit the university for astronomy talks and viewing with the MacAdam Student Observatory.Part 2 Astronomy is an observational, not experimental, science. We cannot directly measure the temperature, density, or energy source for a star or galaxy. We discover these things by quantitative spectroscopy, the careful study of the observed spectrum. Astronomical sources are usually far from equilibrium. Their spectra depend on a number of thermal, plasma, chemical, and condensed matter processes. Analytical solutions are not possible. The code Cloudy solves all of this, numerically, to predict the spectrum. These predictions are compared that observations to infer properties of a star or galaxy. Cloudy is one of the more widely used theory codes in astrophysics with more than 300 papers citing its documentation per year.Cloudy has long solved these problems using available computers and atomic data. The simulations can be improved as computers become more powerful and the atomic data more accurate. We are developing techniques to improve modeling of the dense gas found near black holes or exploding stars. A full treatment of the "Rydberg levels," the highly excited orbits of electrons around ions, is the key improvement. This work will have an influence well beyond this project because of Cloudy's broad community use.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.