Making More Realistic Galaxy Clusters: Confronting AMR Cosmological Simulations of Thermal and Nonthermal Processes with Observations

星系团可以用来约束宇宙常数等宇宙学参数，是暗物质和暗能量的重要探测器。然而，由于它们在诸如宇宙射线和磁场等非线性热和非热过程中的系统不确定性，它们在这些角色中的应用受到限制。本项目的重点是使用先进的自适应网格细化（AMR）宇宙磁流体力学（MHD） n体计算机模拟，并受多波长观测的物理约束。首席研究员使用以前的NSF资金来开发框架，以支持使用Enzo计算机代码的这些研究。在提议的项目中，云，一个新的辐射冷却计算机软件模块，将与三种不同的分布式加热模型相结合——恒星粒子，大质量星系结构和活动星系核。这些对模拟的补充将有助于提供更真实的星系团演化模型，这将提高我们对星系团性质的一般理解，例如当前质量估计中的偏差和使用星系团作为精确宇宙学探测器的局限性。该项目建立在以前nsf资助的开发模拟集群进化代码的工作基础上。提出的更先进的模拟将为解释即将到来的Sunyaev-Zeldovich效应、弱透镜、无线电和x射线调查奠定重要而及时的基础。这项提议的工作将非常出色地将模拟与光谱中无线电、x射线和伽马射线部分的观测结果紧密匹配。这项工作处于此类研究的前沿。首席研究员提供了几种方法来扩大这个项目的影响。在教育方面，(1)将有一名博士后和一名研究生参与并指导该项目；(2)将模块整合到本科和研究生课程中，教授大尺度结构形成和宇宙湍流等物理原理。为了向公众宣传，宇宙学模拟将被纳入当地的公共天文馆项目，并免费分发给全国其他天文馆。最后，首席研究员将使开发的软件模块公开可用，以造福整个科学界。

Clusters of galaxies can be used to constrain cosmological parameters such as the cosmological constant and are an important probe of dark matter and dark energy. However, their use in these roles is limited by their remaining systematic uncertainties in such nonlinear thermal and nonthermal processes, such as cosmic rays and magnetic fields. This project is focused on using advanced adaptive mesh refinement (AMR) cosmological magnetohydrodynamic (MHD) N-body computer simulations with physics constrained by multiwavelength observations. The principal investigator used previous NSF funding to develop the framework to support these investigations using the Enzo computer code. In the proposed project, Cloudy, a new radiative cooling computer software module, will be combined with three different models for distributed heating---star particles, massive galaxy constructs, and active galactic nuclei. These additions to the simulations will help provide more realistic modeling of cluster evolution that will improve our general understanding of cluster properties, such as biases in current mass estimation and limitations of using clusters as probes of precision cosmology.The project builds on previous NSF-funded work on developing code to simulate cluster evolution. The proposed more advanced simulations will lay important and timely groundwork for interpreting upcoming Sunyaev-Zeldovich Effect, weak lensing, radio, and X-ray surveys. The proposed work will do an excellent job of closely matching simulations with observations in the radio, X-ray, and gamma-ray portions of the spectrum. This work is at the forefront of such investigations.The principal investigator offers several ways to extend the impact of this project. Educationally, (1) a postdoctoral fellow and a graduate student will participate and be mentored in the project, and (2) modules will be integrated into undergraduate and graduate coursework to teach such physical principles as large scale structure formation and turbulence in the Universe. For public outreach, cosmological simulations will be incorporated into public planetarium programs locally and freely distributed nationally to other planetariums. Finally, the principal investigator will make the developed software modules publicly available to the benefit of the entire scientific community.