WoU-MMA: Tuning In to the Echoes of Black Hole Seeds

星系的生命和它们的中心超大质量黑洞（SMBH）是不可分割地交织在一起的，并且在宇宙的时间里一起进化。中等质量黑洞（IMBH； 100 - 100万太阳质量）可能是超大质量黑洞的“种子”，尽管人们对连接前者和后者的机制知之甚少，而且很难用电磁辐射来观察。该研究项目将使用计算机模拟来模拟三种不同的黑洞形成机制，以预测黑洞合并的红移、质量和速率。这些引力波特征将被下一代引力波望远镜探测到，比如ESA/NASA的激光干涉仪空间天线（LISA）。首席研究员还将通过一项新的社区大学研究和指导计划，增加对STEM领域服务不足社区学生的招聘和保留。本研究的主要目标是预测从早期宇宙到当前时代的IMBH合并的引力波信号。为了实现这一目标，将使用最先进的宇宙流体动力学模拟来研究它们在早期宇宙中的形成和演化。主要数据将包括大量高分辨率的模拟星系样本，这些样本包含了一整套黑洞物理学。这些模拟将考虑三种不同的IMBH形成机制：单个大质量星族III恒星的坍缩，星团和整个分子云复合体，并将首次以自一致的方式额外包括引力反冲的影响。然后，首席研究员将推断出每个模拟中黑洞合并的速率、质量和质量比，跟踪在其宿主星系内IMBH向SMBHs的整体增长，并计算每种IMBH对LISA观测到的引力波信号的贡献。这些合并事件不太可能发出任何光，因此它们的发现将是对SMBHs形成和成长的非凡看法。IMBHs对引力波信号的贡献还没有被详细建模，因为关于它们的形成和演化还有很多悬而未决的问题。提出的研究将为在星系演化背景下进行涉及早期IMBH形成的理论预测和正确解释LISA探测奠定基础。因此，这个项目推进了NSF宇宙大构想窗口的目标。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。

The lives of galaxies and their central super-massive black holes (SMBH) are inextricably intertwined, and have evolved together over cosmic time. Intermediate-mass black holes (IMBH; 100 – 1-million solar masses) are presumably the “seeds” of the SMBH, though the mechanism(s) connecting the former to the latter are poorly understood and very difficult to observe using electromagnetic radiation. This research program will use computer simulations to model three distinct IMBH formation mechanisms in order to predict the redshifts, masses and rates of IMBH mergers. These gravitational wave signatures will be detectable with the next generation of gravitational wave telescopes like ESA/NASA’s Laser Interferometer Space Antenna (LISA). The principal investigator will also increase the recruitment and retention of students from under-served communities in STEM fields through a new community college research and mentoring program. The primary objective of this research is the prediction of gravitational wave signals of IMBH mergers from the early universe to the current epoch. To accomplish this objective state-of-the-art cosmological hydrodynamical simulations will be used to study their formation and evolution in the early universe. The primary data will consist of a large sample of high-resolution simulated galaxies that incorporate a full suite of black hole physics. These simulations will consider three different IMBH formation mechanisms: the collapse of individual massive Population III stars, clusters of stars, and entire molecular cloud complexes, and will additionally include the effects of gravitational recoil in a self-consistent manner for the first time. The principal investigator will then deduce the rates, masses, and mass ratios of black hole mergers in each simulation, track the overall growth of IMBHs into SMBHs within their host galaxies, and calculate the contribution of each type of IMBH to the gravitational wave signal observable by LISA. These merger events are unlikely to emit any light, and thus their discovery will be an extraordinary view into the formation and growth of SMBHs. The contribution of IMBHs to the gravitational wave signal has not been modeled in detail because there are so many unanswered questions about their formation and evolution. The proposed research will be foundational to making theoretical predictions involving early IMBH formation in the context of galaxy evolution and for correctly interpreting LISA detections. This project thus advances the goals of the NSF Windows on the Universe Big Idea.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.