Collaborative Research: Deploying Curvilinear Coordinate and Multipatch Methods on Neutron Star Mergers

合作研究：在中子星合并中部署曲线坐标和多面体方法

• 批准号: 2110339
• 负责人: Julian Krolik
• 金额: $ 30万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2110339&HistoricalAwards=false
• 关键词: Collaborative; Research; Deploying; Curvilinear; Coordinate

This award supports research in relativity and relativistic astrophysics and it addresses the priority areas of NSF's "Windows on the Universe" Big Idea. The recent observations of a binary neutron star merger using both gravitational wave interferometers and the full spectrum of electromagnetic telescopes has initiated the age of multimessenger astronomy and astrophysics. The rapidly increasing rate of new GW detections by LIGO, VIRGO, and other upcoming similar interferometers and major astronomical facilities is expected to bring an unprecedented wealth of observational evidence from these sources in the near future. This award will fund a collaborative research effort at the Rochester Institute of Technology and the Johns Hopkins University into the latter stages of neutron star mergers, in particular long-lived hypermassive neutron stars that collapse to black holes and stable neutron stars. The effort also includes development of new computational tools required for these calculations. Particular attention will be paid to the roles of the equation of state and total mass as determinants of final properties such as magnetic fields. Magnetic fields underly much of what happens because they support both accretion and jets.Simulations of a wide range of astrophysical events, including strong sources of both electromagnetic and gravitational wave signals, will require numerical tools that can handle an increasingly wide range of microphysical treatments, characteristic scales, and levels of complexity. On the other hand, many astrophysical systems exhibit approximate symmetries that can be leveraged to reduce the total computational cost. By choosing coordinate topologies that mirror the approximate symmetries, or multiple coordinate patches, one can obtain higher simulation accuracies at lower computational costs. Spherical polar grids are optimally suited for a host of applications in relativistic astrophysics. However, the often severe Courant stability limitation of these methods have made them prohibitively expensive. This project is to develop new coding infrastructures to overcome these limitations and apply them to perform highly-accurate, but also very fast simulations of hypermassive neutron star remnants. On the other hand, multipatch method, while computational more complex than single spherical patches, are ideal for simulations of jets around these compact objects. In addition to developing new algorithms, this award will be used train a postdoc and a graduate student in highly-parallelized computing. It will also provide material for educating students in multimessenger astronomy and high-performance computing, and enhance public outreach through a variety of channels, including both an REU program in multimessenger astronomy and a summer program giving underrepresented minority undergraduates experience in physics research. Further educational benefits will accrue through improvements in undergraduate science education. Scientific visualizations from the proposed simulations will be used as a vehicle for public outreach events on science and computing through annual community-wide public exhibits. There will also be benefits to the broader scientific community: both the new simulation tools and the output data sets will be made public.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.

该奖项支持相对论和相对论天体物理学的研究，并解决了NSF“宇宙之窗”大理念的优先领域。最近利用引力波干涉仪和全光谱电磁望远镜对中子星星合并的观测开启了多信使天文学和天体物理学的时代。LIGO、VIRGO和其他即将到来的类似干涉仪和主要天文设施对新GW的探测率迅速增加，预计在不久的将来将从这些来源带来前所未有的丰富观测证据。该奖项将资助罗切斯特理工学院和约翰霍普金斯大学的合作研究工作，进入中子星星合并的后期阶段，特别是长寿命的超大质量中子星坍缩成黑洞和稳定的中子星。 这项工作还包括开发这些计算所需的新计算工具。将特别注意状态方程和总质量作为最终性质（如磁场）的决定因素的作用。 磁场是大部分现象的基础，因为它们支持吸积和喷流。模拟广泛的天体物理事件，包括电磁波和引力波信号的强源，将需要能够处理越来越广泛的微物理处理、特征尺度和复杂程度的数值工具。另一方面，许多天体物理系统表现出近似对称性，可以利用这些对称性来降低总的计算成本。通过选择反映近似对称性的坐标拓扑或多个坐标补丁，可以以较低的计算成本获得较高的仿真精度。 球面极坐标网格最适合于相对论天体物理学中的许多应用。然而，这些方法的通常严重的柯朗稳定性限制使得它们过于昂贵。 这个项目是开发新的编码基础设施，以克服这些限制，并应用它们来执行高精度，但也非常快的超大质量中子星星遗迹的模拟。另一方面，多面体方法，而计算更复杂的比单一的球面补丁，是理想的模拟这些紧凑的对象周围的射流。 除了开发新的算法外，该奖项还将用于培训一名博士后和一名研究生进行高度并行计算。 它还将为教育学生提供多信使天文学和高性能计算的材料，并通过各种渠道加强公众宣传，包括REU多信使天文学计划和暑期计划，为代表性不足的少数民族大学生提供物理研究经验。 进一步的教育效益将通过本科科学教育的改进而增加。 拟议模拟的科学可视化将通过每年的全社区公共展览，用作科学和计算公共外联活动的工具。 这也将有利于更广泛的科学界：无论是新的模拟工具和输出数据集将被公之于众。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。