Collaborative Research: A joint theoretical and experimental approach to low-temperature dielectronic recombination data for photoionized astrophysical environments

本研究项目是由三所大学的研究人员合作开展的理论和实验相结合的研究介电复合(DR) -星光电离的天体物理等离子体中控制电荷平衡的关键过程。研究人员将计算天文学上重要的原子离子的DR率，并在与太空相关的低温条件下在实验室中进行高精度测量。准确的DR率只适用于少数元素，因此这项研究中产生的数据将使天文学家能够准确地确定天文环境中的元素丰度和电离平衡。研究人员将对学生进行与天体物理学相关的高级理论和实验原子物理研究方法的培训，并为K-12学生的科学推广活动做出贡献。研究人员将使用大规模的多构型半相对论和全相对论电子结构计算来确定高质量的DR速率系数，将它们与现有的半相对论计算进行比较，并将它们与在低温离子储存环中进行的精确实验测量进行基准测试。该项目将对等电子序列的DR数据进行系统计算和基准测试，目的是为原子数据库和天体物理建模代码提供准确的数据。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。

This research project is a collaborative effort between researchers from three universities to undertake a combined theoretical and experimental study of dielectronic recombination (DR) – a key process controlling the charge balance in astrophysical plasmas ionized by starlight. The researchers will calculate the rates of DR for astronomically important atomic ions and measure them in the laboratory to high accuracy for the low temperatures relevant to space. Accurate DR rates are only available for a handful of elements, so the data generated in this study will allow astronomers to accurately determine the elemental abundances and ionization balance in astronomical environments. The investigators will train students in methods of advanced theoretical and experimental atomic physics research relevant to astrophysics and contribute to science outreach activities for K-12 students.The researchers will use large-scale multi-configuration semi-relativistic and fully relativistic electronic structure calculations to determine high quality DR rate coefficients, compare them to available semi-relativistic calculations, and benchmark them to accurate experimental measurements performed in cryogenic ion storage rings. The project will systematically calculate and benchmark DR data for isoelectronic sequences with the goal of providing accurate data to atomic databases and astrophysical modeling codes.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.