DCL: HBCU: Computational Atomic Laboratory Astrophysics for Stellar and Nebular Spectral Diagnostics

原子光谱——原子的独特能量特征——携带着关于发现原子的天文环境的物理条件的重要信息。这个研究项目的主要目标是精确计算在恒星和太空气体云中发现的原子的关键特性。这些性质的准确值将使天文学家能够可靠地分析这些遥远天体的原子光谱，并推断那里存在的条件。该项目将在高级计算研究方法方面培养一名研究生和一名博士后研究员，并将增加未被充分代表的少数民族学生对研究的参与。这个研究项目将研究“铁峰”元素，以更好地利用它们作为晚期恒星和气体星云大气的诊断探测器。研究人员将使用创新的计算方法和数值代码计算出Fe II、Cr II、Ti II和Sc II单电荷离子的精确光电离截面、辐射和碰撞速率以及电子激发速率。研究中产生的准确数据将允许对恒星和星云区域进行可靠的光谱分析，因为原子数据的不确定性被认为是铁峰元素单变化离子的测量丰度与计算丰度之间差异的主要来源。新的数据将被整合到广泛使用的建模代码CLOUDY中，并将通过CHIANTI等原子数据库提供给天文社区。该项目将在计算实验室天体物理技术方面培养一名研究生和一名博士后研究员，并将为在高级计算研究方面培养代表性不足的少数民族学生提供机会。

Atomic spectra---the unique energy signatures of atoms---carry important information about the physical conditions of the astronomical environments in which the atoms are found. The main goal of this research project is to perform accurate calculations of key properties of atoms that are found in stars and gas clouds in space. Accurate values of these properties will allow astronomers to reliably analyze atomic spectra from these distant astronomical objects and infer the conditions present there. The project will train a graduate student and a postdoctoral researcher in methods of advanced computational research, and it will increase the participation of underrepresented minority students in research.This research project will study "iron-peak" elements to better exploit them as diagnostic probes of the atmospheres of late-type stars and gaseous nebulae. The researchers will calculate accurate photoionization cross-sections, radiative and collisional rates, and electron excitation rates for the singly charged ions Fe II, Cr II, Ti II, and Sc II using innovative computational methods and numerical codes. Accurate data generated in the study will allow reliable spectral analysis of stellar and nebular regions because uncertainties in atomic data are thought to be a major source of discrepancy between the measured and calculated abundances of singly changed ions of the iron-peak elements. The new data will be incorporated into the widely used modeling code CLOUDY, and they will be made available to the astronomical community via atomic databases such as CHIANTI. The project will train a graduate student and a postdoctoral researcher in computational laboratory astrophysics techniques, and it will provide opportunities to train underrepresented minority students in advanced computational research.