Stars, Black Holes, and Disks: Dense Matter Phenomena in 2D Numerical Relativity

恒星、黑洞和圆盘：二维数值相对论中的稠密物质现象

• 批准号: 2110287
• 负责人: Matthew Duez
• 金额: $ 20.47万
• 依托单位: Washington State 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: 2021-08-15 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2110287&HistoricalAwards=false
• 关键词: Stars; Black; Holes; Disks; Dense

This award supports research in relativity and relativistic astrophysics and it addresses the priority areas of NSF's "Windows on the Universe" Big Idea. A great deal can be learned about the extremes of strong gravity, about denser-than-nuclei matter, and even about the origin of heavy elements, by studying the collisions of neutron stars with each other or with black holes. Such a binary system emits gravitational waves as the neutron star and its companion spiral together and electromagnetic waves (visible light, infrared, gamma rays, etc.) after the merger. Both signals are sometimes detectable and in some cases have been detected. Numerical simulations that include general relativity are the only way to predict how merger processes unfold, and they've gotten pretty good at modeling the merger and the first few hundredths of a second afterward. The post-merger evolution lasts around a couple of seconds. Although this does not sound long, it is too long to be accessible to 3D numerical simulations, especially because the presence of small-scale turbulent flows makes the grids needed large and the simulations expensive. This project will probe these later times with numerical relativity, following the story of the merger through to completion, when nothing but a stable, quiescent black hole or neutron star remains. The problems of large grid and long time requirements will be dealt with by carrying out 2D simulations (using the rough symmetry about a rotation axis) and carefully-designed models of the effect of turbulent flows on scales to small to be directly captured on the 2D grids. These simulations will include a high degree of realism in the treatment of magnetic fields and neutrino radiation. The techniques and code developed to carry them out will be applicable to other interesting systems with near-axisymmetry, such as collapsing stars.This award supports long-time (multi-second) studies of these strong-gravity, dense-matter systems using the Spectral Einstein Code (SpEC), a high-accuracy numerical relativity code that includes magnetohydrodynamics, nuclear microphysics, and neutrino transport. SpEC's 2D radiation magnetohydrodynamics code will be improved to include 2D spacetime evolution, Monte Carlo neutrino transport, and a mean-field/large-eddy incorporation of the effects of turbulence in the azimuthal direction. Long-time 2D simulations will extend existing compact binary merger simulations for multiple seconds, yielding accurate predictions about disk winds, winds from and possible delayed collapse of a stellar remnant, and GRB energetics. Finally, these numerical techniques will be applied to the first SpEC simulations of black hole formation and growth in a post-collapse, long-duration GRB scenario.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”大构想的优先领域。通过研究中子星之间或黑洞之间的碰撞，我们可以了解到很多关于极端强引力的知识，关于密度大于原子核的物质，甚至关于重元素的起源。这样的双星系统在合并后会发射引力波（中子星和伴星一起旋转）和电磁波（可见光、红外线、伽马射线等）。这两种信号有时可以检测到，在某些情况下已经检测到。包括广义相对论在内的数值模拟是预测合并过程如何展开的唯一方法，它们已经很好地模拟了合并和之后最初的百分之几秒。合并后的进化大约持续几秒钟。虽然这听起来并不长，但对于三维数值模拟来说，它太长了，特别是因为小规模湍流的存在使得所需的网格变大，模拟成本也很高。这个项目将用数值相对论来探索这些后来的时间，跟随合并的故事直到完成，那时只有一个稳定的、静止的黑洞或中子星留下。大网格和长时间要求的问题将通过进行二维模拟（使用关于旋转轴的粗略对称）和精心设计的湍流影响模型来处理，这些模型的规模小到可以直接捕获在二维网格上。这些模拟将包括对磁场和中微子辐射处理的高度真实性。为执行它们而开发的技术和代码将适用于其他具有近轴对称的有趣系统，例如坍缩的恒星。该奖项支持使用爱因斯坦谱码（SpEC）对这些强引力、致密物质系统进行长时间（多秒）的研究，这是一种高精度的数值相对论代码，包括磁流体力学、核微物理和中微子输运。SpEC的二维辐射磁流体动力学代码将得到改进，包括二维时空演化、蒙特卡罗中微子输运，以及在方位方向上湍流效应的平均场/大涡合并。长时间的二维模拟将把现有的紧凑型双星合并模拟延长数秒，从而对星盘风、恒星残骸的风和可能的延迟坍缩以及GRB能量学做出准确预测。最后，这些数值技术将应用于第一次SpEC模拟黑洞的形成和成长，在坍缩后，长时间的GRB场景。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Late-time post-merger modeling of a compact binary: effects of relativity, r-process heating, and treatment of transport

• DOI: 10.1088/1361-6382/acc0c6
• 发表时间: 2022-08
• 期刊: Classical and Quantum Gravity
• 影响因子: 3.5
• 作者: Milad Haddadi;Matthew D. Duez;F. Foucart;T. Ramirez;Rodrigo Fernández;Alexander L Knight;Jerred Jesse-Jerre

Nonlinear mode-tide coupling in coalescing binary neutron stars with relativistic corrections

• DOI: 10.1103/physrevd.106.083001
• 发表时间: 2021-07
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Fatemeh Hossein Nouri;S. Bose;Matthew D. Duez;A. Das

Simulating magnetized neutron stars with discontinuous Galerkin methods

• DOI: 10.1103/physrevd.105.123031
• 发表时间: 2021-09
• 作者: N. Deppe;F. H'ebert;Lawrence E. Kidder;William Throwe;Isha Anantpurkar;C. Armaza;G. Bonilla;M. Boyle;H. Chaudhary;Matthew D. Duez;Nils L. Vu;F. Foucart;M. Giesler;Jason S. Guo;Yoonsoo Kim;Prayush Kumar;I. Legred;Dongjun Li;G. Lovelace;Sizheng Ma;A. Macedo;D. Melchor;M. Morales;Jordan Moxon;Kyle C. Nelli;É. O’Shea;H. Pfeiffer;T. Ramirez;H. Ruter;Jennifer A. Sanchez;M. Scheel;Sierra Thomas;D. Vieira;Nikolas A. Wittek;T. Włodarczyk;S. Teukolsky