Gravitational-Wave Data Analysis and Population Inference

该奖项支持相对论和相对论天体物理学的研究，它解决了NSF“宇宙之窗”大构想的优先领域。引力波是阿尔伯特·爱因斯坦预言的时空涟漪，自2015年美国国家科学基金会的激光干涉引力波天文台（LIGO）首次直接探测到引力波以来，引力波一直是天体物理学领域的一大福音。这些引力波在宇宙中传播了数十亿光年到达地球，并携带着它们最初是如何产生的线索。到目前为止，黑洞和中子星的剧烈碰撞产生了近100个引力波，并为黑洞的性质、核物理学、恒星的天体物理学和宇宙膨胀提供了一个很好的实验平台。根据该奖项，西北大学的研究小组将分析在先进干涉仪时代的第四次观测中收集的数据，以表征引力波，并最终了解黑洞和中子星如何在宇宙中相互接触的故事。他们的发现将通过开源代码库、引人注目的可视化、公开讲座和实践研讨会，以及为K-12教师提供天体物理学研究经验的项目，传播给天体物理学社区以及更广泛的公众。在LIGO-Virgo-KAGRA干涉仪网络的第四次观测中，预计会有大量的探测结果，这将给引力波天体物理学家带来新的计算和组织挑战。与此同时，探测到的引力波的更大样本将带来新的问题，在某些情况下，关于黑洞和中子星双星的形成和演化的确切答案。西北大学的研究小组将开发一个具体的框架来分析双星合并源的数量，扩展解释观测到的数量属性的能力，并帮助计划未来的观测运行。与此同时，他们将在新发现中识别异常的引力波事件，并研究它们如何挑战我们最好的理解，并推动黑洞和中子星天体物理学的前沿。具体来说，该团队将针对一些问题：评估事件触发的重要性，从探测集合中推断人口，以及与简单模型的比较，这些模型可以回答关于黑洞和中子星对如何形成并最终相互碰撞的目标问题。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。

This award supports research in relativity and relativistic astrophysics, and it addresses the priority areas of NSF's "Windows on the Universe" Big Idea. Gravitational waves, ripples in space-time predicted by Albert Einstein, have been a major boon to the field of astrophysics since they were first directly detected in 2015 by NSF's Laser Interferometric Gravitational-Wave Observatory (LIGO). These gravitational waves travel billions of light years across the universe to Earth and carry clues about how they were originally produced. The violent collisions of black holes and neutron stars have been responsible for the nearly 100 gravitational waves detected so far and provide an excellent testbed for the nature of black holes, nuclear physics, astrophysics of stars, and the expansion of the universe. Under this award, the team at Northwestern University will analyze data collected in the fourth observing run of the advanced interferometer era to characterize gravitational waves and ultimately understand the story of how black holes and neutron stars come into contact with each other in the universe. Their findings will be disseminated to both the astrophysics community as well as the broader public through open-source code bases, eye-catching visualizations, public lectures and hands-on workshops, and a program offering astrophysics research experiences for K-12 teachers.The large number of detections expected in the fourth observing run of the LIGO-Virgo-KAGRA interferometer network will present new computational and organizational challenges for gravitational-wave astrophysicists. At the same time, larger samples of detected gravitational waves will bring to light new questions and in some cases firm answers regarding the formation and evolution of black-hole and neutron-star binaries. The Northwestern University group will develop a concrete framework to analyze the population of binary merger sources, expand abilities for interpretation of the observed population properties, and help plan future observing runs. In parallel, they will identify exceptional gravitational-wave events among the new discoveries and investigate how they may challenge our best understanding and push the frontiers of black-hole and neutron-star astrophysics. Specifically, the team will target a number of problems: the assessment of the significance of event triggers, population inferences from the ensemble of detections, and comparisons with simple models that answer targeted questions about how pairs of black holes and neutron stars come to be and eventually collide with one another.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.