Gravitational Wave Physics and Astrophysics with LIGO

该奖项支持相对论和相对论天体物理学的研究，并解决了NSF“宇宙之窗”大理念的优先领域。引力波（GW）物理学和天文学已经进入了一个新时代：LIGO和Virgo探测器在前三次观测运行（O 1，O2，O3）中探测到的GW瞬态事件（到目前为止，来自包含黑洞和/或中子星的紧凑双星系统的合并）是频繁的。在第四次观测运行（O 4）中，预计将于2022年12月开始并持续一年，KAGRA探测器也将参与其中，LIGO和Virgo探测器对遥远源的灵敏度将有所提高。这将导致从紧凑的双星合并中发现GW的前所未有的速度，以及从其他天体物理来源（如随机GW背景）发现许多GW的潜力。事实上，可能会发现全新类别的GW源。 这些观测将使从基础物理学到天文学、天体物理学和宇宙学的大量研究成为可能。双星黑洞合并的观测被用来了解恒星演化和双星的形成、演化和死亡。它们使得在强场、高度动态的引力体系中对广义相对论进行独特而有力的检验成为可能。双中子星星合并的观测使约束的核状态方程，独特的测量本地哈勃-勒梅特参数，并深入了解宇宙中元素形成的起源。拟议的工作与LIGO实验室和LIGO，Virgo和KAGRA（LVK）合作组织协调，重点是开发方法，以便使用高度优化的搜索管道，在嘈杂的数据中自信地识别来自天体物理源的弱GW信号，并在天体物理背景下解释结果。这些方法将得到进一步发展，并应用于LVK O 4运行的数据，所吸取的经验教训将纳入未来观测运行的适当准备工作。为了让更多的人和团体能够了解引力波科学的进展，我们组织了一系列的活动，包括当地中学的学生和教师，指导暑期本科生研究员，以及组织和参与GW开放数据研讨会。这项工作致力于发现和分析LIGO中的引力波（GW）信号，Virgo和KAGRA探测器在FY 2023-FY 2025期间（LIGO的观测运行O 4和O 5）。具体的科学目标是：（a）使用LSC的两个“旗舰”搜索管道PyCBC和gstlal，从LIGO、Virgo和KAGRA的数据中识别来自紧凑型二元合并的GW信号;（B）通过搜索合并后的GW“回波”，搜索来自CBC的GW中的非张量极化，（c）对来自紧凑双星合并的GW信号的强引力透镜进行更深入的搜索-GW事件对的识别，包括亚阈值事件候选者，以及联合参数估计;（d）提高单事件天体物理参数估计的效率和稳健性，以便准确无误地推断致密天体的质量和自旋;（e）利用O 4和O 5的大得多的事件计数来进一步发展我们对BBH合并速率作为质量、自旋和宇宙学红移的函数的理解。这项工作将建立在所有这些努力的现有专业知识和经验的基础上，并通过自动化日常任务将其扩展到频繁检测的时代。这些努力的结果将使人们有可能在GW事件变得频繁时对其进行可靠的检测，并及时向LSC，天文学界和公众提供所获得的信息，以便这些社区可以充分利用它们来推进引力波天文学。为了使引力波科学获得广泛的人群和团体，将开展以下活动：在LIGO SURF/REU计划中培训和指导各种各样的本科生;通过GW开放科学中心支持开放科学;组织和参加年度GW开放数据研讨会;利用科学计算作为一种工具，通过在线教程和对当地学校STEM教师的宣传，吸引高中生和本科生;并参与K-12外展活动，与公众沟通，通过访问当地的中高层，该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的评估来支持。影响审查标准。

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-wave (GW) physics and astronomy has entered a new era: GW transient events (so far, from the merger of compact binary systems containing black holes and/or neutron stars) detected with the LIGO and Virgo detectors in their first three observing runs (O1, O2, O3) are frequent. In the fourth observing run (O4), estimated to begin in December 2022 and continuing for one year, the KAGRA detector will also participate, and the LIGO and Virgo detectors will have increased sensitivity to distant sources. This will result in unprecedented rates of discovery of GWs from compact binary mergers, and the potential for many discoveries of GWs from other astrophysical sources such as a stochastic GW background. Indeed, entirely new classes of GW sources may be discovered. These observations will enable a wealth of studies, ranging from fundamental physics to astronomy, astrophysics and cosmology. Observations of binary black hole mergers are used to understand stellar evolution and the formation, evolution and death of binaries. They enable uniquely powerful tests of general relativity in the strong-field, highly-dynamical regime of gravity. Observations of binary neutron star mergers enable constraints on the nuclear equation of state, unique measurements of the local Hubble-Lemaitre parameter, and insights into the origins of element formation in the universe. The proposed work, in coordination with the LIGO Laboratory and LIGO, Virgo and KAGRA (LVK) Collaborations, focuses on the development of methods to confidently identify weak GW signals from astrophysical sources in the noisy data, using highly optimized search pipelines, and interpret the results in their astrophysical context. These methods will be further developed and applied to data from the LVK O4 run, and lessons learned will be incorporated into appropriate preparation for future observing runs. A variety of activities involving students and teachers from local middle and high schools, mentoring summer undergraduate research fellows, and organizing and participating in GW Open Data Workshops, aim to make these advances in gravitational wave science accessible to a broad range of people and groups.This work is devoted to discovering and analyzing gravitational-wave (GW) signals in the LIGO, Virgo and KAGRA detectors during FY2023-FY2025 (LIGO's observing runs O4 and O5). Specific scientific goals are: (a) Identifying GW signals from compact binary mergers in data from LIGO, Virgo, and KAGRA, using two of the LSC "flagship" search pipelines, PyCBC and gstlal; (b) performing ever more sensitive Tests of General Relativity as the theory of strong-field gravity governing binary black hole (BBH) mergers, through searches for post-merger GW "echoes", searches for non-tensorial polarizations in GWs from CBCs, and searches for beyond-GR parameters in signal waveforms from BBH mergers; (c) performing ever deeper searches for strong gravitational lensing of GW signals from compact binary mergers - the identification of GW event pairs, including sub-threshold event candidates, and joint parameter estimation; (d) improving the efficiency and robustness of single-event astrophysical parameter estimation to infer the masses and spins of the compact objects with accuracy and precision; and (e) using the much larger event count from O4 and O5 to further develop our understanding of the BBH merger rate as a function of mass, spin, and cosmological redshift. The work will build on existing expertise and experience in all of these efforts, and extend them to the era of frequent detections by automating routine tasks. The results of these efforts will make it possible to make confident detections of GW events as they become frequent, and make the information obtained available to the LSC, to the astronomical community, and to the public, promptly, so that they can be fully exploited by those communities to advance gravitational-wave astronomy. In order to make gravitational wave science accessible to a broad range of people and groups, the following activities will be pursued: training and mentoring a diverse range of undergraduate students in the LIGO SURF/REU program; supporting open science through the GW Open Science Center; organizing and participating in annual GW Open Data Workshops; using scientific computing as a tool to engage high school and undergraduate students through online tutorials and through outreach to STEM teachers at local schools; and engaging in K-12 outreach and communicating with the general public, through visits to local middle- and high-school STEM fairs and classrooms.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.