Collaborative Research: Wou-MMA: Multi-Messenger Signatures of Massive Black Hole Binaries

多年来，人们已经知道，几乎每个星系的中心都有一个比太阳大数百万到数十亿倍的黑洞(BH)。随着宇宙时间的推移，这些大质量黑洞中的一些将聚集在一起，形成一个大质量黑洞双星(MBHB)，并最终合并。MBHBs还会共生附近的物质，这种聚积流动对合并本身有重要影响。佐治亚理工学院和弗吉尼亚大学之间的一项研究合作将有助于回答这样一个问题：在聚合的大质量黑洞双星附近，吸积流的性质是什么？这个问题的答案直接影响到联合探测电磁(EM)和引力波(GW)信号的可行性。这样的探测被认为是下一个观测上的重大挑战，它将提供对这些大质量天体的演化和增长的更全面的了解。由于预期未来将由脉冲星定时阵列(PTA)和激光干涉仪空间天线(LISA)进行探测，该团队将研究沉浸在吸积流中的MBHBs的重合电磁和GW特征。该计划有三个目标，它们是对拟议的研究的补充，并由研究人员作为科学家和教育者的角色实现。第一，通过妇女和代表性不足群体成员的直接参与，促进科技、经济、技术和经济领域的多样性。二是根据本项目的理念，在教与学方面进行创新。第三个目标将通过继续致力于公众参与和外展来实现。该计划还将指导一名博士后研究员和一名研究生的研究、培训和指导。拟议的研究计划集中在一套使用辐射-磁流体动力学(RMHD)程序Athena++的高分辨率模拟上，该程序将跟踪MBHBs在PTA和LISA频段的演化。这项研究的目标是为首次模拟具有辐射转移的MBHBs的吸积奠定基础，并预测由此产生的GW信号的EM对应物(光谱和光曲线)。它的优点包括对形成双星吸积的基本物理过程的理解的进步，以及对注定要合并的鼓舞人心的MBHBs的改进的多信使搜索。这一研究计划所取得的成果与一系列地面和天基天文台以及天体物理学中的几个研究领域有关，包括致密天体物理、活动星系核、星系演化和宇宙学。这个项目推进了NSF宇宙大理想之窗的目标。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。

It has been known for many years that a black hole (BH), millions to billions of times more massive than the Sun, resides in the heart of nearly every galaxy. Over cosmic time, some of these massive BHs will come together, forming a massive black hole binary (MBHB), and eventually merge. MBHBs also accrete nearby matter, and this accretion flow has an important impact on the merger itself. A research collaboration between Georgia Institute of Technology and the University of Virginia will help to answer the question, what are the properties of accretion flows in the vicinity of coalescing massive black hole binaries? The answer to this question has direct implications for the feasibility of coincident detections of electromagnetic (EM) and gravitational wave (GW) signals from coalescences. Such detections are considered the next observational grand challenge that will provide a more complete understanding of evolution and growth of these massive objects. In anticipation of future detections by the Pulsar Timing Arrays (PTAs) and Laser Interferometer Space Antenna (LISA), this team of collaborators will investigate the coincident EM and GW signatures of MBHBs immersed in accretion flows. There are three goals of this program that are complementary to the proposed research and enabled by the investigators' roles as scientists and educators. The first is to promote diversity in STEM through direct participation of women and members of underrepresented groups. The second is to introduce innovations in teaching and learning based on ideas drawn from this project. The third will be reached through a continued commitment to public engagement and outreach. This program will also result in mentoring of one postdoctoral researcher and research training and mentoring of one graduate student. The proposed program of research centers on a suite of high-resolution simulations with the radiation-magnetohydrodynamic (RMHD) code Athena++, which will follow MBHBs as they evolve through the PTA and LISA frequency bands. The goal of this study is to set the stage for the first simulations of accreting MBHBs with radiative transfer and to predict the resulting EM counterparts (spectra and light curves) to GW signatures. Its merits include the advancement in understanding of fundamental physical processes that shape accretion onto binaries and improved multi-messenger searches for inspiraling MBHBs bound for coalescence. Findings enabled by this research program are relevant for an array of ground- and space-based observatories and several research areas within astrophysics, including the physics of compact objects, active galactic nuclei, galaxy evolution and cosmology. This project advances the goals of the NSF Windows on the Universe Big Idea.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.