Realistic Simulations of the Intergalactic Medium: The Search for Missing Physics - Part 2

星际介质的真实模拟：寻找缺失的物理现象 - 第 2 部分

• 批准号: 1810774
• 负责人: Michael Norman
• 金额: $ 0.78万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-05-01 至 2019-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1810774&HistoricalAwards=false
• 关键词: Realistic; Simulations; Intergalactic; Medium; Search

The intergalactic medium (IGM) is the hot, X-ray emitting gas that permeates the space between galaxies. Currently, standard numerical simulation cannot match several key observational features of the IGM. The mismatch between the simulations and observation data is much too large to be caused by observational errors, and is seen in multiple comparisons using different statistics, and by different groups. This project proposes to resolve this open question in astrophysics by running very high resolution simulations on the Blue Waters supercomputer to make more accurate and robust estimates of the IGM. Furthermore, the simulations and codes will be publicly available to allow others to make their own estimates from existing or new observations.The project will simulate the hydrogen Lyman alpha forest (LYAF) using the newly developed extreme scale branch of the Enzo called Enzo-P. Enzo-P implements the rich suite of physics models from the widely used Enzo community code on top of a new, highly scalable AMR infrastructure called Cello. Both Enzo-P and Cello have been developed by the PIs group at UCSD. The combination of Enzo-P and Cello will permit for the first time the use of AMR throughout a large cosmological volume, removing the existing tradeoff between large volume statistics and high local resolution that characterized previous Enzo simulations. The project will apply this new capability to carry out simulations of the LAF with sufficiently high resolution to capture the gaseous halos of galaxies which contribute significantly to intergalactic absorption, while at the same time surveying a statistically significant volume of the universe. Moreover, the project will construct synthetic LYAF spectra and analyze their statistical properties to see whether the inclusion of high column density absorbers in the model improves agreement observations.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.

星系间介质 (IGM) 是一种炽热的 X 射线气体，弥漫在星系之间的空间中。 目前，标准数值模拟无法匹配 IGM 的几个关键观测特征。 模拟和观测数据之间的不匹配太大，不可能是由观测误差引起的，并且可以在使用不同统计数据和不同组的多重比较中看到。该项目建议通过在 Blue Waters 超级计算机上运行非常高分辨率的模拟来解决天体物理学中的这一悬而未决的问题，从而对 IGM 进行更准确和稳健的估计。 此外，模拟和代码将公开，以便其他人根据现有或新的观测结果做出自己的估计。该项目将使用新开发的 Enzo 极端规模分支 Enzo-P 来模拟氢莱曼阿尔法森林 (LYAF) 。 Enzo-P 在名为 Cello 的新型、高度可扩展的 AMR 基础设施之上，从广泛使用的 Enzo 社区代码中实现了丰富的物理模型套件。 Enzo-P 和 Cello 都是由 UCSD 的 PI 小组开发的。 Enzo-P 和 Cello 的结合将首次允许在整个大宇宙体积中使用 AMR，消除了先前 Enzo 模拟所特有的大体积统计数据和高局部分辨率之间现有的权衡。该项目将应用这一新功能以足够高的分辨率对 LAF 进行模拟，以捕获对星系间吸收有显着贡献的星系气态晕，同时调查具有统计意义的宇宙体积。 此外，该项目将构建合成的 LYAF 光谱并分析其统计特性，以了解模型中包含高柱密度吸收体是否可以改善观察结果的一致性。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力评估进行评估，认为值得支持。优点和更广泛的影响审查标准。