Collaborative Research: WoU-MMA Constraining the nuclear equation of state and population of neutron star mergers through observations of transient and persistent phenomena

中子星（NSs）是在大质量恒星生命结束时形成的：恒星的外层在剧烈爆炸中被抛射出去，但恒星的核心坍塌形成一个小而致密的残骸。形成双星系统的NSs与另一个NSs有时呈螺旋状并合并，产生引力波和比新星（所谓的千新星）亮数千倍的明亮瞬变。nsf资助的激光干涉仪引力波天文台（LIGO）已经探测到NS-NS合并。来自罗切斯特理工学院和田纳西大学诺克斯维尔分校的一个团队将继续他们的项目，使用先进的计算模型来更好地理解NS-NS合并和NS物理。他们将产生千新星爆炸的真实模型，改进对中子质量分布的估计，并更好地了解中子星的数量。这些模型将以引力波和NS-NS合并的电磁探测为基准。该项目包括培养和指导研究生和博士后研究人员；参加罗彻斯特理工学院（Rochester Institute of Technology）的一个项目（ROAR），该项目将来自少数族裔的高中生引入研究领域；田纳西大学诺克斯维尔分校开设了一门以引力波为重点的新本科课程。该提案的详细科学目标是；扩展正在进行的工作，以产生更系统的千新星模型，校准模拟和探索相关的系统不确定性；将快速r-过程观测系统地纳入关于NS种群特性和状态方程（EOS）的联合推断中，允许替代方案，以评估r-过程元素的起源；使用作为该计划一部分开发的工具来重建NS种群，核EOS和r过程元素的起源；并评估这些工具得出这些推论的能力。提出的研究包括制作中子星碰撞合并时发生的千新星爆炸的真实模型。这些模型将以引力波和NS-NS合并的电磁探测为基准，从而改进对中子质量分布的估计，更好地了解中子星种群。因此，该项目与“宇宙之窗：多信使天文学（WoU-MMA）大构想”的科学任务是一致的。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Neutron stars (NSs) are formed when a massive star reaches the end of its life: the outer layers of the star are ejected in a violent explosion but the core of the star collapses to form a small, dense remnant. NSs that form a binary system with another NS sometimes in-spiral and merge, producing gravitational waves and a bright transient that is thousands of times more luminous than a nova (a so-called kilonova). NS-NS mergers have been detected by the NSF-funded Laser Interferometer Gravitational wave Observatory (LIGO). A team from the Rochester Institute of Technology and the University of Tennessee Knoxville will continue their program to use advanced computational models to better understand NS-NS mergers and NS physics. They will produce realistic models of the kilonova explosion, improve estimates of the neutron mass distribution, and better understand neutron star populations. The models will be benchmarked against gravitational wave and electromagnetic detections of NS-NS mergers. The program includes training and mentoring of graduate students and postdoctoral researchers; participation in a Rochester Institute of Technology program (ROAR) that introduces high school students from underrepresented minorities to research; and development of a new undergraduate course at the University of Tennessee Knoxville focused on gravitational waves. The detailed science goals of the proposal are; extend ongoing work to produce more systematic kilonova models, calibrated to simulations and exploring relevant systematic uncertainties; incorporate rapid r-process observations systematically into joint inference about NS population properties and the equation of state (EOS), allowing for alternatives, to assess the origin of r-process elements; use the tools developed as part of this program to reconstruct the population of NS, the nuclear EOS, and the origin of r-process elements; and assess the ability of the tools to draw these inferences. The proposed research involves producing realistic models of the kilonova explosion that occurs when neutron stars collide and merge. These models will be benchmarked against gravitational wave and electromagnetic detections of NS-NS mergers, thereby improving estimates of the neutron mass distribution and better understanding neutron star populations. Thus, this project is aligned with the science mission of the Windows on the Universe: Multi-Messenger Astronomy (WoU-MMA) 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.