Modeling Extreme Astrophysical Black Hole Binaries

引力波(GW)天文学有望提供一种革命性的新宇宙观，可以探测以前无法探索的区域，包括中子星的内部，黑洞的碰撞，其发出的能量超过整个可见宇宙的亮度，甚至大爆炸的残余物。然而，挑战是巨大的，因为GW信号将隐藏在更大数量级的噪声中。为了获得对宇宙动力学的新洞察，GW天文学家需要能够从观测到的信号中推断出源的性质。然而，只有在高精度已知波形对源参数的依赖关系的情况下，才能从观测信号中提取这些源的物理参数。因此，GW天文学工作的成功关键取决于数值相对论(NR)的进步。该奖项资助了罗切斯特理工学院(RIT)久负盛名的研究计划，该计划旨在对高度非线性区域中的合并黑洞双星进行建模，这是a LIGO/AdVirgo最响亮的信号源之一。我们专注于技术困难的小质量比、高自旋和高进动区域的双星，这需要在代码优化、新的规范条件(特别是适用于高自旋区域的规范条件)、高自旋和线性动量的非共形平坦初始数据以及混合数值/微扰技术方面的新发展，这些技术将使我们能够使用相对较少的数值模拟来模拟大范围的双星。我们的主要目标将是从这些极端双星产生足够精度的波形，用于LIGO/AdVirgo GW数据分析，并对高进动双星的引力辐射反冲(以及剩余质量和自旋)进行建模，以阐明这些反冲的分布及其如何影响超大质量黑洞的分布和增长。鉴于aLIGO计划于2015年上线，这项研究非常及时。我们的研究将直接惠及aLIGO/AdVirgo计划、忍者计划和NRAR计划，以及天体物理学中一个新兴的新领域：探索合并和后退黑洞的观测结果。这里提出的研究将补充我们NR小组正在进行的其他项目，将物质和磁场包括在我们的真空广义相对论代码中，以便研究紧凑天体合并的EM对应物，并对超大质量黑洞附近的吸积盘动力学进行建模。这一奖项不仅将使私人投资机构能够加强他们的研究计划，而且还将用于极大地加强RIT的整体研究努力。该奖项支持RIT天文学博士项目的研究生研究，以及拟议中的“建模和计算”新博士项目。重要的是，我们的研究将是我们与RIT的国家聋人技术研究所建立的新合作伙伴关系的重点，该项目由NSF资助，将创新的舞蹈和戏剧表演相结合，向聋人和重听社区推广科学。可视化还将成为科学、数学和计算方面的公共推广活动的一种工具，通过现场访问和年度社区范围的公共展览(如ImagineRIT)。

Gravitational Wave (GW) Astronomy promises to provide a revolutionary new view of the universe that can probe previously unexplorable regions, including the interiors of neutron stars, collisions of black holes, which emit energy at luminosities exceeding the entire visible universe, and even remnants of the big bang. However, the challenges are significant because the GW signals will be hidden in orders of magnitude larger noise. To gain new insight into the dynamics of the universe, GW astronomers need to be able to infer the nature of the sources from the observed signals. However, the physical parameters of these sources can only be extracted from the observed signals if the dependence of the waveform on source parameters is known to high-accuracy. The success of the GW astronomy efforts therefore depends critically on advancements in Numerical Relativity (NR). This award funds the well-established research program at the Rochester Institute of Technology (RIT) to model merging black hole binaries in the highly-nonlinear regime, which are among the loudest sources for aLIGO/AdVirgo. We focus on binaries in the technically difficult small-mass-ratio, highly-spinning, and highly-precessing regimes, which requires new developments in code optimization, new gauge conditions (especially gauge conditions adapted for the high-spin regime), non-conformally flat initial data for high spins and linear momentum, as well as hybrid numerical/perturbative techniques that will allow us to model a large range of binaries using relatively few numerical simulations. Our principle goals will be to produce waveforms from these extreme binaries of sufficient accuracy for aLIGO/AdVirgo GW data analysis, and to model the gravitational radiation recoil (as well as remnant mass and spins) from highly-precessing binaries in order to elucidate the distributions of these recoils and how they affect the distribution and growth of supermassive black holes. This research is very timely now that aLIGO is scheduled to come online in 2015. Our research will directly benefit the aLIGO/AdVirgo project, the NINJA and NRAR projects, and an emerging new field in astrophysics: The search for the observational consequences of merging and recoiling black holes. The research proposed here will complement other ongoing projects of our NR group to include matter and magnetic fields in our vacuum general relativistic code in order to study EM counterparts to compact-object mergers and to model accretion disk dynamics near supermassive black holes. This award will not only enable the PIs to enhance their research program, but it will also be used to greatly enhance the research effort at RIT as a whole. The award supports graduate student research in RIT's PhD Astronomy program and a proposed new PhD program in 'Modeling and Computation'. Importantly, our research will be the focus of our new partnership with RIT's National Technical Institute for the Deaf on an NSF-funded project that combines innovative dance and theater performances to promote science to the deaf and hard-of-hearing communities. Visualizations will also be a vehicle for public outreach events on science, mathematics, and computing through site visits and annual community-wide public exhibits like 'ImagineRIT'.