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

星系和它们的中心超大质量黑洞(SMBH)的生命是密不可分的，并且随着宇宙时间的推移而一起进化。中等质量黑洞(IMBH；1亿-100万太阳质量)可能是SMBH的“种子”，尽管连接前者和后者的机制(S)鲜为人知，也很难用电磁辐射进行观测。这项研究计划将使用计算机模拟来模拟三种不同的IMBH形成机制，以预测IMBH合并的红移、质量和速率。下一代引力波望远镜，如欧空局/美国宇航局的激光干涉仪太空天线(LISA)，将可以探测到这些引力波信号。首席调查员还将通过一项新的社区大学研究和辅导计划，增加STEM领域服务不足社区的学生的招生和留住。这项研究的主要目的是预测从早期宇宙到现在的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。主要数据将由包含一整套黑洞物理的高分辨率模拟星系的大样本组成。这些模拟将考虑三种不同的IMBH形成机制：单个大质量群体III恒星的坍塌、星团和整个分子云复合体，并将首次以自洽的方式另外包括引力反冲的影响。然后，首席研究员将在每次模拟中推导出黑洞合并的速率、质量和质量比，跟踪在其所在星系内IMBH变成SMBH的总体增长，并计算每种类型的IMBH对LISA可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芒，因此它们的发现将是对SMBH的形成和发展的一个非同寻常的视角。IMBH对引力波信号的贡献还没有得到详细的模拟，因为关于它们的形成和演化还有很多悬而未决的问题。这项拟议的研究将为在星系演化的背景下做出有关早期IMBH形成的理论预测和正确解释LISA探测奠定基础。这个项目因此推进了NSF宇宙大理想之窗的目标。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.