Correlating the Gravitational Wave and Electromagnetic Sky Maps

最近从双星黑洞(BBH)、双星中子星(BNS)和黑洞-中子星(BHNS)系统合并中探测到的引力波(GW)开启了GW和多信使天体物理领域的序幕。到目前为止，已经观察到近100个这样的系统。先进的GW探测器有望进一步提高其灵敏度，并在未来3-5年内进行更长时间的观测运行。这些即将到来的运行的主要目标之一是探测随机引力波背景(SGWB)，它是通过总结宇宙中所有合并的BBH、BNS和BHNS系统的GW而产生的。该项目将推动对SGWB的研究进入宇宙结构形成的新探索。它将通过将SGWB测量与电磁(EM)观测相关联来实现这一点，例如对天空中星系分布的观测或引力弱透镜的观测。该项目将使本科生和研究生都能积极参与这一新兴领域的高知名度研究，并将通过明尼苏达大学和更广泛的一系列研究和外联活动和倡议，促进妇女和代表性不足的少数群体的参与。该项目将开发两种形式来测量SGWB各向异性与宇宙中大尺度结构的EM示踪剂之间的相关性。一种形式将建立在现有的互相关技术上，以测量GW能量密度的各向异性。另一种是利用现有的参数估计管道进行紧凑型二进制合并，从而显著(~1000倍)提高此类合并对SGWB的敏感度。这两种形式将应用于在即将到来的第四次和第五次高级LIGO和高级处女座探测器观测运行中获得的数据。他们还将利用即将到来的欧几里德调查，这将彻底改变对星系在最大尺度上分布的理解。将这些GW和EM类型的主要数据集与最先进的分析管道相结合，将产生更灵敏的SGWB-EM关联测量结果，有可能首次检测到这种关联，并开始约束天体物理和宇宙模型。该项目将把乔治华盛顿大学的天体物理学家和传统天文学家聚集在一起，并将加强这两个社区之间的联系。参与该项目的学生将有独特的机会与GW和传统天文学社区的专家密切合作，并在定义新兴的新天体物理学和宇宙学探测器方面发挥主导作用。该项目还将汇集世界各地的专家，特别是来自欧洲、印度和美国的专家，从而加强国际科学界的联系。由于该团队包括50%的女性，将通过与明尼苏达大学适当的团体和组织联系，并参与他们的活动、会议和对当地学校的访问，大力促进女性参与天体物理学。该奖项反映了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。

Recent detections of gravitational waves (GWs) from the mergers of binary black hole (BBH), binary neutron star (BNS), and black hole-neutron star (BHNS) systems have initiated the fields of GW and multi-messenger astrophysics. Nearly 100 such systems have been observed to date. Advanced GW detectors are expected to further improve their sensitivities, and to conduct extended observing runs in the next 3-5 years. One of the primary targets of these upcoming runs is the detection of the stochastic gravitational-wave background (SGWB) that arises by summing up GWs from all merging BBH, BNS, and BHNS systems in the universe. This project will promote the study of the SGWB into a new probe of the formation of structure in the universe. It will do so by correlating the SGWB measurements with electromagnetic (EM) observations, such as observations of the galaxy distribution on the sky or gravitational weak lensing. The project will enable strong participation of both undergraduate and graduate students in high-visibility studies in this emerging field, and it will promote participation of women and underrepresented minorities through a series of research and outreach activities and initiatives at the University of Minnesota and more broadly. The project will develop two formalisms to measure correlations of SGWB anisotropy with EM tracers of the large scale structure in the universe. One formalism will build on the existing cross-correlation techniques to measure anisotropy in the GW energy density. The other will leverage existing parameter estimation pipelines for compact binary mergers, hence dramatically (~1000x) increasing the sensitivity to the SGWB due to such mergers. The two formalisms will be applied to the data acquired in the upcoming fourth and fifth observing runs of Advanced LIGO and Advanced Virgo detectors. They will also take advantage of the upcoming Euclid survey that will revolutionize the understanding of the galaxy distribution on the largest scales. Combining these premier data sets, of both GW and EM flavors, with the state-of-the-art analysis pipelines will result in orders-of-magnitude more sensitive SGWB-EM correlation measurements, with a potential to detect such correlations for the first time and start constraining astrophysical and cosmological models. The project will bring together GW astrophysicists and traditional astronomers, and will serve to strengthen the connections between the two communities. Students participating in the project will have unique opportunities to closely work with experts in both GW and traditional astronomy communities, and to play leading roles in defining the emerging new astrophysics and cosmology probes. The project will also bring together experts across the world, specifically from Europe, India, and the United States, hence strengthening the ties across the international scientific community. As the team includes 50% women, a strong effort will be made to promote involvement of women in astrophysics by connecting with appropriate groups and organizations at the University of Minnesota and participating in their activities, meetings, and visits to local schools.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.