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.

播层间介质（IGM）是热的X射线发射气体，可渗透到星系之间的空间。 当前，标准数值模拟无法匹配IGM的几个关键观察特征。 模拟和观察数据之间的不匹配太大而无法由观察错误引起，并且在使用不同统计数据和不同组的多次比较中可以看到。该项目建议通过在蓝色水域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开放问题，以对IGM进行更准确，更强大的估计。 此外，将公开使用模拟和代码，以允许其他人从现有或新观察结果中进行自己的估计。该项目将使用称为Enzo-P的Enzo的新开发的极限分支模拟氢Lyman Alpha Forest（Lyaf）。 Enzo-P在新的，高度可扩展的AMR基础架构（称为大提琴）的基础上，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和大提琴都由UCSD的PIS组开发。 ENZO-P和大提琴的组合将首次允许在大型宇宙学量中使用AMR，从而消除了大型量统计数据和较高的本地分辨率之间的现有权衡，这些分辨率表征了先前的Enzo模拟。该项目将采用这种新的能力，以足够高的分辨率进行LAF的模拟，以捕获星系的气态光环，这些星系对造影术产生了显着贡献，同时对统计学上具有统计学意义的宇宙进行了调查。 此外，该项目将构建合成的LYAF光谱并分析其统计特性，以查看在模型中包含高柱密度吸收器是否改善了协议的观察结果。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的审查标准来通过评估来支持的。