Collaborative Research: An Empirical Blueprint for the Gravitational-Wave Background

在星系中心的超大质量黑洞被认为会产生非常低频率的引力波，通过正在进行的脉冲星定时阵列项目，可以通过仔细计时来自恒星的无线电脉冲的到达来检测。预计来自许多这些系统的组合信号将产生背景噪声，可能很快被脉冲星定时阵列检测到。该项目将使用一种新的方法，基于对吸积超大质量黑洞的观测，来估计这种背景噪声的强度以及它在引力波频率中的分布。该项目将使用这种新方法提供一个框架，一旦检测到背景噪声，就可以确定超大质量黑洞的生长历史。该项目还将在新泽西和纽约建立一个脉冲星搜索合作实验室中心，让高中生使用真实的数据搜索脉冲星。该项目将利用不同红移下类星体光度函数的观测结果，结合双活动星系核的局部观测结果，建立超大质量黑洞双星的宇宙学分布模型，这将有助于在脉冲星定时阵列观测中发现随机引力波背景。这种方法是对现有基于星系合并模拟的方法的补充。新方法将确定可以通过探测引力波背景来约束的关键物理参数。该项目还将在新泽西和纽约建立一个脉冲星搜索合作实验室中心。脉冲星搜索合作实验室是美国国家科学基金会长期支持的一个项目，允许高中学生用真实的无线电数据搜索脉冲星。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Orbiting supermassive black holes in the centers of galaxies are thought to produce very low frequency gravitational waves that could be detected by careful timing of the arrival of radio pulses from pulsars through the ongoing pulsar timing array project. It is expected that the combined signals from many of these systems will produce a background noise that may soon be detectable by pulsar timing arrays. This project will use a new method based on observations of accreting supermassive black holes to provide an estimate of the strength of this background noise as well as it's distribution in gravitational wave frequencies. The project will use this new method to provide a framework for determining the history of the growth of supermassive black holes once the background noise is detected. The project will also create a Pulsar Search Collaboratory hub in New Jersey and New York that will involve high school students in the search for pulsars using real data. This award advances the goals of the Windows on the Universe Big Idea.The project will use observations of quasar luminosity functions at different redshifts combined with local observations of dual Active Galactic Nuclei to build an empirically-based model of the cosmological distribution of supermassive black hole binaries that will contribute to the stochastic gravitational wave background expected to be detected in pulsar timing array observation. This approach is complementary to the existing approach that is based on galaxy merger simulations. The new approach will determine key physical parameters that can be constrained through detection of the gravitational wave background. The project will also create a Pulsar Search Collaboratory hub in New Jersey and New York. The Pulsar Search Collaboratory is a long-standing NSF supported program that allows high schools students to search for pulsars with real radio data. It is a low-barrier way for students to experience science and scientific discovery.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.