Collaborative Research: Modelling the Turbulent Galaxy Formation

合作研究：模拟湍流星系的形成

• 批准号: 1412107
• 负责人: Andrey Kravtsov
• 金额: $ 43.47万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1412107&HistoricalAwards=false
• 关键词: Collaborative; Research; Modelling; Turbulent; Galaxy

Anywhere that there is a fluid in motion, whether liquid or gas, there will be turbulence. These disturbances to the flow can be very significant, but their possibly profound effect on the formation of galaxies out of the cosmic gas remains an area of mystery in our fundamental understanding of how the Universe evolves. This work seeks to correct this lack, using high powered computers to carry out novel numerical simulations with very high resolution. For the first time, pretty well all of the physics involved in forming stars within galaxies will be included. The calculations will be intimately connected with telescope data, both checking the computer results and helping to understand the observations. The new ideas will also be useful for other studies of turbulent fluids.Cosmic gas flows have high velocities, span enormous scales, and are highly turbulent, but the possibly profound effects of turbulence on galaxy formation are largely unexplored. This project is a systematic exploration of turbulence and its effects on accretion flows, star formation, and the structure of galaxies, in self-consistent cosmological simulations using adaptive mesh refinement (AMR). Part of the work will implement and test a novel model for sub-grid scale turbulence and use it to estimate local turbulent stresses. This model will be used to add new physically-motivated prescriptions for star formation into the galaxy formation simulations, incorporating a rich set of physical processes thought to be critical for comparison with observations, including modeling of molecular hydrogen, chemical enrichment and evolution, dust formation and destruction, radiative transfer of ionizing and far-ultraviolet radiation, star formation, and stellar feedback with radiation pressure and cosmic rays. Observational comparisons will test and inform the theoretical models, while the simulation results will help to understand the data. Scientific results will include quantifying the effects of turbulence on the cold accretion gas flows onto galaxies, assessing the relative contribution of dynamical drivers of turbulence, and quantifying the effects of turbulence on the density structure of the gas. The emphasis on observational comparisons will make this study particularly valuable for interpreting the results from current and future facilities. Both the methods and the results will be of value for other simulations and for semi-analytic models. The simulations also lend themselves well to high-fidelity, scientifically-accurate visualizations well suited to the high resolution environment of full-dome planetarium projectors, but of value to all planetaria.

任何有运动的流体的地方，无论是液体还是气体，都会出现湍流。 这些对流动的扰动可能非常显着，但它们对宇宙气体中星系的形成可能产生的深远影响仍然是我们对宇宙如何演化的基本理解中的一个谜团。 这项工作旨在纠正这一缺陷，使用高性能计算机以非常高分辨率进行新颖的数值模拟。 这是第一次，几乎所有与在星系内形成恒星有关的物理学都将被包括在内。 计算将与望远镜数据密切相关，既检查计算机结果又有助于理解观测结果。 这些新想法也将有助于湍流流体的其他研究。宇宙气流具有高速度、跨越巨大尺度并且高度湍流，但湍流对星系形成可能产生的深远影响在很大程度上尚未被探索。 该项目是在使用自适应网格细化（AMR）的自洽宇宙学模拟中系统地探索湍流及其对吸积流、恒星形成和星系结构的影响。 部分工作将实施和测试亚网格尺度湍流的新模型，并用它来估计局部湍流应力。 该模型将用于在星系形成模拟中添加新的恒星形成物理驱动处方，纳入一系列被认为对于与观测结果进行比较至关重要的物理过程，包括分子氢建模、化学富集和演化、尘埃形成和破坏、电离和远紫外辐射的辐射转移、恒星形成以及辐射压力和宇宙射线的恒星反馈。 观察比较将测试并告知理论模型，而模拟结果将有助于理解数据。 科学成果将包括量化湍流对星系中冷吸积气流的影响，评估湍流动力学驱动因素的相对贡献，以及量化湍流对气体密度结构的影响。 对观察比较的强调将使这项研究对于解释当前和未来设施的结果特别有价值。 这些方法和结果对于其他模拟和半解析模型都很有价值。 这些模拟还非常适合高保真、科学准确的可视化，非常适合全圆顶天文馆投影仪的高分辨率环境，但对所有天文馆都有价值。