Mergers, Stars, and Disks: Dense Matter Phenomena in Numerical Relativity

合并、恒星和圆盘：数值相对论中的稠密物质现象

• 批准号: 1806207
• 负责人: Matthew Duez
• 金额: $ 18万
• 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: 2018
• 资助国家: 美国
• 起止时间: 2018-08-15 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1806207&HistoricalAwards=false
• 关键词: Mergers; Stars; Disks; Dense; Matter

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. One such merger of two neutron stars has recently been observed in gravitational waves and across the electromagnetic spectrum. Astronomers now know that such events happen and that they release tremendous amounts of radiation and material, but exactly how this release happens in a merger aftermath remains unclear. Numerical simulations that include general relativity are the only way to predict how merger processes unfold, but these simulations are made incredibly difficult by the presence of turbulence, which creates fluid flow and magnetic field features across a wide range of length scales. Small-scale flows do drive changes in the merger remnant at large scales and so cannot be ignored. Although computer simulations cannot yet directly capture all of this dynamics, a great deal can be learned with current computing capabilities by parameterized exploration of unresolved small-scale effects and post-merger initial states. This project will pursue these strategies to shed light on how these exotic and violent events produce their outflows and radiation. Carrying out these simulations will involve training both graduate and undergraduate students on techniques of computer modeling in relativistic astrophysics. The resulting gravitational wave and nuclear debris data will be made available to all astronomers working to detect and characterize these events.The Washington State University will study three core problems of numerical relativity--inspiraling binaries, differentially rotating neutron stars, and hyperaccreting black holes--using the Spectral Einstein Code (SpEC), a high-accuracy numerical relativity code that includes magnetohydrodynamics, nuclear microphysics, and neutrino transport. Inspiral simulations will study equation of state effects on gravitational waves, and improvements to evolution algorithms and smooth, causal equation of state parameterizations will be explored. Post-merger dynamics of NSNS systems will be modeled, focusing on the case of a hypermassive neutron star remnant. Simulations will track the secular evolution to collapse under the influence of neutrino radiation, large-scale magnetic fields, and subgrid-scale turbulence. Finally, neutrino effects around black hole-torus systems will be analyzed using neutrino transport methods.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.

可以通过研究中性恒星相互互相碰撞或与黑洞的碰撞来了解有关强度的极端，较密集的重力，甚至是重型元素的起源。 最近在重力波和电磁频谱中观察到了两颗中子星的一项合并。 现在，天文学家知道这些事件发生了，并且它们释放了大量的辐射和物质，但是在合并后，这种释放是如何在合并之后发生的。包括一般相对性的数值模拟是预测合并过程如何展开的唯一方法，但是由于存在湍流，这些模拟使这些模拟变得非常困难，从而在各种长度尺度上创造了流体流量和磁场特征。 小规模的流确实可以在大尺度上驱动合并残留物的变化，因此不能忽略。 尽管计算机模拟还不能直接捕获所有这些动态，但是通过当前的计算功能可以通过参数化探索未解决的小规模效应和合并后初始状态来学习很多。 该项目将采取这些策略来阐明这些异国情调和暴力事件如何产生其流出和辐射。 进行这些模拟将涉及培训研究生和本科生在相对论天体物理学中的计算机建模技术。 The resulting gravitational wave and nuclear debris data will be made available to all astronomers working to detect and characterize these events.The Washington State University will study three core problems of numerical relativity--inspiraling binaries, differentially rotating neutron stars, and hyperaccreting black holes--using the Spectral Einstein Code (SpEC), a high-accuracy numerical relativity code that includes magnetohydrodynamics, nuclear微物理学和中微子转运。 Inspiral模拟将研究状态对重力波的影响的方程，并将探讨对进化算法的改进和光滑的状态参数方程。 NSNS系统的合并后动力学将进行建模，重点是高质量中子恒星残留物的情况。 模拟将在中微子辐射，大规模磁场和亚根机尺度的湍流的影响下跟踪世俗进化以塌陷。 最后，将使用中微子运输方法分析黑洞吹牛系统中的中微子效应。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的影响审查标准通过评估来支持的。

项目成果

Numerical relativity of compact binaries in the 21st century

• DOI: 10.1088/1361-6633/aadb16
• 发表时间: 2018-08
• 期刊: Reports on Progress in Physics
• 影响因子: 18.1
• 作者: Matthew D. Duez;Y. Zlochower

Numerical simulations of neutron star-black hole binaries in the near-equal-mass regime

• DOI: 10.1103/physrevd.99.103025
• 发表时间: 2019-03
• 期刊: Physical Review D
• 影响因子: 5
• 作者: F. Foucart;Matthew D. Duez;Lawrence E. Kidder;S. Nissanke;H. Pfeiffer;M. Scheel

Gravitational waveforms from spectral Einstein code simulations: Neutron star-neutron star and low-mass black hole-neutron star binaries

• DOI: 10.1103/physrevd.99.044008
• 发表时间: 2018-12
• 期刊: Physical Review D
• 影响因子: 5
• 作者: F. Foucart;Matthew D. Duez;T. Hinderer;Jesus Caro;A. Williamson;M. Boyle;A. Buonanno;R. Haas;D. Hemberger;Lawrence E. Kidder;H. Pfeiffer;M. Scheel

Systematic effects from black hole-neutron star waveform model uncertainties on the neutron star equation of state

黑洞-中子星波形模型不确定性对中子星状态方程的系统影响

• DOI: 10.1103/physrevd.99.024049
• 发表时间: 2019
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Chakravarti, Kabir;Gupta, Anuradha;Bose, Sukanta;Duez, Matthew D.;Caro, Jesus;Brege, Wyatt;Foucart, Francois;Ghosh, Shaon;Kyutoku, Koutarou;Lackey, Benjamin D.
• 通讯作者: Lackey, Benjamin D.

High-accuracy waveforms for black hole-neutron star systems with spinning black holes

• DOI: 10.1103/physrevd.103.064007
• 发表时间: 2020-10
• 期刊: Physical Review D
• 影响因子: 5
• 作者: F. Foucart;A. Chernoglazov;M. Boyle;T. Hinderer;Marleen L. Miller;Jordan Moxon;M. Scheel;N. Deppe-N.