A New Spin: The Next Generation of Gravitational-Wave Searches for Merging Black Holes

目前引力波对黑洞和中子星合并信号的搜索非常成功，使我们能够探索新的天体物理学并测试强场引力。然而，这些搜索还没有开始进入引力波信号的完整、丰富的发现空间。特别是，如果双星黑洞具有大的、不对准的自转和不对称的质量，那么双星的轨道将前进。由此产生的引力波可能具有显著的幅度和相位调制，导致目前的搜索完全错过了信号。然而，对这些调制的测量将使我们能够解开各种二进制参数，使得在强重力条件下能够比目前的探测更准确地探测基础物理。该奖项支持开发搜索和潜在地检测这类重要的进动信号所需的工具。此外，这项工作将为与PI一起参与这项研究的本科生提供数据分析技能培训，特别是通过马萨诸塞大学达特茅斯大学的COMPLETE计划，该计划旨在提高低收入、高成就本科生的STEM学位完成率。该奖项支持的工作将使用双管齐下的方法访问有趣的进动双黑洞类别。PI和一名博士生将设计并执行引力波搜索，使用对进动波形的两次谐波近似来搜索中等进动的双星系统，从而能够利用单独谐波的良好形态。此外，该小组将设计并执行引力波搜索，使用参数空间受限区域上的匹配过滤器统计的推广，对高度进动的双星系统进行搜索。这些搜索将部署在档案引力波数据上，可能会探测到前进的引力波信号，或者对这类系统的合并速度设定有意义的上限。这一奖项所带来的开发工作总体上将为未来更复杂的搜索工作提供信息，特别是在我们转向第三代引力波探测器的时候。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。

Current gravitational-wave searches for signals from merging black holes and neutron stars have been extraordinarily successful, allowing us to probe new astrophysics and test strong-field gravity. However, these searches have not yet begun to access the full, rich discovery space of gravitational-wave signals. In particular, if binary black holes have large, misaligned spins and asymmetric masses, then the binary’s orbit will precess. The resulting gravitational waves can have significant amplitude and phase modulations, causing the signals to be missed entirely by current searches. However, measurement of these modulations would allow us to disentangle various binary parameters, enabling more accurate probes of fundamental physics in the strong-gravity regime than are possible with current detections. This award supports the development of tools needed to search for and potentially detect this important class of precessing signals. Additionally, this work will provide data-analysis skill training for undergraduates participating in this research with the PI, particularly through the ACCOMPLISH program at the University of Massachusetts Dartmouth which seeks to increase STEM degree completion of low-income, high achieving undergraduates. The work supported by this award will access the interesting class of precessing binary black holes using a two-pronged approach. The PI and a PhD student will design and perform a gravitational-wave search for moderately-precessing binary systems using a two-harmonic approximation to the precessing waveform, enabling the exploitation of the well-behaved morphology of the separate harmonics. Additionally, the group will design and perform a gravitational-wave search for highly-precessing binary systems using a generalization of the matched-filter statistic over a constrained region of parameter space. These searches will be deployed over archival gravitational-wave data, potentially making a detection of a precessing gravitational-wave signal or setting meaningful upper limits on the rates of mergers of such systems. The development work enabled by this award will inform future directions for more complex searches in general, particularly as we move to the third generation of gravitational-wave detectors.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.