{"title":"具有天体物理学重要意义的单电离氮光谱线的原子数据","authors":"M. C. Li and W. Li","doi":"10.3847/1538-4357/ad779b","DOIUrl":null,"url":null,"abstract":"Nitrogen lines are widely observed in astrophysical spectra and provide important diagnostics for plasma properties. In this work, we present extended calculations for accurate energy levels, electric dipole radiative transition parameters, and lifetimes for the lowest 102 states of the 2s22p2, 2s2p3, 2s2p23s, 2s22p{n1l, n2d, 4f}(n1 = 3–5, l = s, p, n2 = 3, 4), and 2p4 configurations of N ii within the framework of the fully relativistic multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction methods. These data are useful for modeling astrophysical spectra, for example, for nitrogen abundance determinations in early B-type stars, and for studying the compositions and plasma properties of H ii regions and planetary nebulae. Our computed transition parameters are compared with available experimental and theoretical data. The accuracy of the calculations is also assessed via a statistical analysis of the differences between the transition rates in the Babushkin and Coulomb gauges and by consideration of cancellation factors. In this way, 201 of the 1656 transitions computed in this work are estimated to be from accurate to better than 3%, corresponding to an accuracy class of A.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Atomic Data for Astrophysically Important Spectral Lines of Singly Ionized Nitrogen\",\"authors\":\"M. C. Li and W. Li\",\"doi\":\"10.3847/1538-4357/ad779b\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Nitrogen lines are widely observed in astrophysical spectra and provide important diagnostics for plasma properties. In this work, we present extended calculations for accurate energy levels, electric dipole radiative transition parameters, and lifetimes for the lowest 102 states of the 2s22p2, 2s2p3, 2s2p23s, 2s22p{n1l, n2d, 4f}(n1 = 3–5, l = s, p, n2 = 3, 4), and 2p4 configurations of N ii within the framework of the fully relativistic multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction methods. These data are useful for modeling astrophysical spectra, for example, for nitrogen abundance determinations in early B-type stars, and for studying the compositions and plasma properties of H ii regions and planetary nebulae. Our computed transition parameters are compared with available experimental and theoretical data. The accuracy of the calculations is also assessed via a statistical analysis of the differences between the transition rates in the Babushkin and Coulomb gauges and by consideration of cancellation factors. In this way, 201 of the 1656 transitions computed in this work are estimated to be from accurate to better than 3%, corresponding to an accuracy class of A.\",\"PeriodicalId\":501813,\"journal\":{\"name\":\"The Astrophysical Journal\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-10-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"The Astrophysical Journal\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.3847/1538-4357/ad779b\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Astrophysical Journal","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3847/1538-4357/ad779b","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
氮线在天体物理光谱中被广泛观测到,并为等离子体特性提供了重要的诊断依据。在这项工作中,我们在完全相对论多构型 Dirac-Hartree-Fock 和相对论构型相互作用方法的框架内,对 N ii 的 2s22p2、2s2p3、2s2p23s、2s22p{n1l, n2d, 4f}(n1 = 3-5, l = s, p, n2 = 3, 4) 和 2p4 构型的最低 102 态的精确能级、电偶极子辐射转变参数和寿命进行了扩展计算。这些数据有助于建立天体物理光谱模型,例如,用于确定早期 B 型恒星的氮丰度,以及研究 H ii 区域和行星状星云的成分和等离子体特性。我们将计算出的过渡参数与现有的实验和理论数据进行了比较。计算的准确性还通过对巴布什金量规和库仑量规中转变率之间差异的统计分析以及对抵消因素的考虑进行了评估。这样,在这项工作中计算出的 1656 个转变中,估计有 201 个转变的精确度在 3% 以上,相当于 A 级精确度。
Atomic Data for Astrophysically Important Spectral Lines of Singly Ionized Nitrogen
Nitrogen lines are widely observed in astrophysical spectra and provide important diagnostics for plasma properties. In this work, we present extended calculations for accurate energy levels, electric dipole radiative transition parameters, and lifetimes for the lowest 102 states of the 2s22p2, 2s2p3, 2s2p23s, 2s22p{n1l, n2d, 4f}(n1 = 3–5, l = s, p, n2 = 3, 4), and 2p4 configurations of N ii within the framework of the fully relativistic multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction methods. These data are useful for modeling astrophysical spectra, for example, for nitrogen abundance determinations in early B-type stars, and for studying the compositions and plasma properties of H ii regions and planetary nebulae. Our computed transition parameters are compared with available experimental and theoretical data. The accuracy of the calculations is also assessed via a statistical analysis of the differences between the transition rates in the Babushkin and Coulomb gauges and by consideration of cancellation factors. In this way, 201 of the 1656 transitions computed in this work are estimated to be from accurate to better than 3%, corresponding to an accuracy class of A.