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，并阐述了美国国家科学基金会“宇宙之窗”大构想的优先领域。引力波是阿尔伯特·爱因斯坦预测的时空涟漪，自2015年由美国国家科学基金会的激光干涉引力波天文台(LIGO)首次直接探测到以来，一直是天体物理学领域的一大福音。这些引力波穿越宇宙数十亿光年到达地球，并携带着关于它们最初是如何产生的线索。黑洞和中子星的猛烈碰撞是迄今探测到的近100个引力波的原因，并为黑洞的性质、核物理、恒星的天体物理和宇宙的膨胀提供了一个极好的试验台。根据这一奖项，西北大学的团队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放源码库、引人注目的可视化、公开讲座和动手研讨会以及一个为K-12教师提供天体物理研究经验的项目向天体物理界以及更广泛的公众传播。LIGO-Virgo-KAGRA干涉仪网络第四次观测中预计会有大量探测，这将给引力波天体物理学家带来新的计算和组织方面的挑战。与此同时，更大的探测到的引力波样本将会带来关于黑洞和中子星双星的形成和演化的新问题，在某些情况下还会有明确的答案。西北大学小组将开发一个具体的框架来分析二元合并源的种群，扩展解释观测种群属性的能力，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特殊的引力波事件，并调查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。具体地说，该团队将针对一些问题：事件触发因素的重要性的评估，从探测集合中进行的人口推断，以及与简单模型的比较，这些简单模型回答了关于黑洞和中子星对如何形成并最终相互碰撞的有针对性的问题。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。

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.