The quest for the cosmic origin of the heavy elements

最近发现的引力波来自中子星星合并的双星及其伴随的电磁对应物，这是物理学和天体物理学历史上的一个分水岭，标志着引力波多信使天文学的开始。紫外线，光学和近红外线发射是一致的热瞬态（'kilonova'），这提供了第一个直接证据的快速中子俘获过程（r-过程）的重元素的形成。尽管60年前人们就认识到，大约一半比铁重的元素是通过快速捕获中子到较轻的种子核上合成的，但这一r过程的天体物理学位置仍然难以捉摸。在未来几年，此类合并的侦破率将大幅提高。与此同时，电磁设施的景观也将大大改善，在整个引力波探测器的灵敏度范围内提供光学和红外跟踪。该计划概述了一项雄心勃勃的研究计划，旨在了解天体物理系统和产生宇宙中r过程元素的基本物理过程。它建立在两个驱动主题上：1）R过程站点：全面研究中子星合并和核心坍缩超新星子类中最有希望的单个站点和R过程机制。2)观察特征：提供详细的r过程丰度模式（与观测结果进行比较），探索宇宙学意义，提供瞬变（千新星，GRB超新星等）的预测在多信使和时域天文学中解释未来的观测结果，并寻找r过程的指纹。该计划将联合收割机计算天体物理学和高性能计算与半解析建模方法相结合。它将提供及时的预测，并确定在多信使和时域天文学即将突破性发现的理论解释的前沿。它还提供了一种直接的方式，将新的实验核数据纳入天体物理现象模型，从而将核设施与宇宙联系起来。在十年的更长时间尺度上，该计划将制定科学目标，以帮助下一代引力波探测器和未来的电磁设施做出新的发现。该研究计划为学生和博士后提供了一个独特的跨学科培训环境，他们将在未来十年物理学和天体物理学最令人兴奋的领域之一的前沿进行研究。他们将获得广泛的技能，包括高性能计算和数值方法的专业知识，这在学术界内外都是非常有价值的。该计划将加强加拿大在多信使天文学时代的领导地位，当时对这一主题的兴趣无与伦比。

The recent discovery of gravitational waves from a binary neutron star merger and its accompanying electromagnetic counterparts was a watershed moment in the history of physics and astrophysics and marked the beginning of multimessenger astronomy with gravitational waves. The ultraviolet, optical, and near--infrared emission was consistent with a thermal transient ('kilonova'), which provided first direct evidence for the formation of heavy elements by the rapid neutron capture process (r-process). Despite the realization 60 years ago that roughly half of the elements heavier than iron are synthesized by rapid capture of neutrons onto lighter seed nuclei, the astrophysical site(s) for this r-process had remained elusive. Over the next years, the detection rate of such mergers will dramatically increase. Simultaneously, the landscape of electromagnetic facilities will also dramatically improve, providing optical and infrared follow-up throughout the sensitivity volume of the gravitational-wave detectors. This proposal outlines an ambitious research program with the aim of understanding the astrophysical systems and fundamental physical processes that generate r-process elements in the Universe. It builds on two driving themes: 1) R-process sites: comprehensive research into the most promising individual sites and mechanisms for the r-process in neutron-star mergers and subclasses of core-collapse supernovae. 2) Observational signatures: provide detailed r-process abundance patterns (to be compared with observations), explore cosmological implications, provide predictions for transients (kilonovae, GRB supernovae etc.) to interpret future observations in multi-messenger and time-domain astronomy and search for fingerprints of the r-process. This program will combine computational astrophysics and high--performance computing with methods of semi--analytic modeling. It will provide timely predictions and define the forefront of the theoretical interpretation of imminent ground-breaking discoveries in multimessenger and time-domain astronomy. It also provides a direct way to incorporate new experimental nuclear data to model astrophysical phenomena and thus to connect nuclear facilities with the cosmos. On longer timescales of a decade, this program will develop science goals to help next-generation gravitational-wave detectors and future electromagnetic facilities make new discoveries. This research program provides a unique inter-disciplinary training environment for students and postdocs who will perform research at the forefront of what will be one of the most exciting fields in physics and astrophysics over the next decade. They will acquire a broad set of skills, including expertise in high--performance computing and numerical methods, which are highly valuable inside and outside of academia. This program will strengthen Canadian leadership in the era of multimessenger astronomy, at a time of unparalleled interest in this subject.