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)是当一颗大质量恒星到达其寿命的尽头时形成的：恒星的外层在剧烈爆炸中被抛出，但恒星的核心坍塌形成一小块致密的残留物。NSS与另一个NS形成双星系统，有时在螺旋中合并，产生引力波和比新星亮度高数千倍的明亮瞬变(所谓的千诺瓦)。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诺克斯维尔大学的一个团队将继续他们的计划，使用先进的计算模型来更好地理解NS-NS合并和NS物理。他们将制作千诺瓦爆炸的真实模型，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NS-NS合并的引力波和电磁探测为基准。该计划包括对研究生和博士后研究人员的培训和指导；参与罗切斯特理工学院的一个项目(Roar)，该项目向来自少数族裔的高中生介绍研究；以及在田纳西诺克斯维尔大学开发一门专注于引力波的新本科课程。该提案的详细科学目标是：扩展正在进行的工作，以产生更系统的千诺瓦模型，根据模拟进行校准，并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种群属性和状态方程(EOS)的联合推理中，以允许替代方案，以评估r过程元素的起源；使用作为该计划的一部分开发的工具来重建NS群体、核EOS和r过程元素的起源；以及评估工具得出这些推断的能力。这项拟议的研究涉及制作中子星碰撞和合并时发生的千诺瓦爆炸的真实模型。这些模型将以NS-NS合并的引力波和电磁探测为基准，从而改进对中子质量分布的估计，并更好地了解中子星的数量。因此，该项目与宇宙之窗：多信使天文学(WOU-MMA)大理想的科学使命相一致。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。

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.