IMPROVED V ii log(gf) VALUES, HYPERFINE STRUCTURE CONSTANTS, AND ABUNDANCE DETERMINATIONS IN THE PHOTOSPHERES OF THE SUN AND METAL-POOR STAR HD 84937
IMPROVED V ii log(gf) VALUES, HYPERFINE STRUCTURE CONSTANTS, AND ABUNDANCE DETERMINATIONS IN THE PHOTOSPHERES OF THE SUN AND METAL-POOR STAR HD 84937
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太阳光层和贫金属恒星 HD 84937 中改进的 V ii log(gf) 值、超精细结构常数和丰度测定
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
J. Cowan
中科院分区：
文献类型：
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作者：
M. P. Wood;J. Lawler;E. A. Den Hartog;C. Sneden;J. Cowan
报告了 203 个 V ii 系的新实验绝对原子跃迁概率。支化分数是根据使用傅里叶变换光谱仪和中阶梯光栅光谱仪记录的光谱来测量的。通过辐射寿命测量对分支分数进行归一化以确定新的跃迁概率。一般来说，这项工作与之前报道的 V ii 转移概率之间存在良好的一致性。两个光谱仪、独立的辐射校准方法和独立的数据分析程序可以减少系统的不确定性，特别是由于光学深度误差引起的不确定性。此外，通过 FTS 光谱中的最小二乘拟合线轮廓，可以测量选定水平的新超精细结构常数。新的 V ii 数据应用于太阳和贫金属恒星 HD 84937 的高分辨率可见光和紫外光谱，以确定新的、更准确的 V 丰度。覆盖一系列波长和激发电位的线用于搜索非 LTE 效应。我们新的太阳光球 V 丰度（来自 15 V ii 线的 log ε(V) = 3.95）与太阳系陨石值之间存在非常好的一致性。在 HD 84937 中，我们从 68 条线得出 [V/H] = -2.08，得出 [V/Fe] = 0.24 的值。
New experimental absolute atomic transition probabilities are reported for 203 lines of V ii. Branching fractions are measured from spectra recorded using a Fourier transform spectrometer and an echelle spectrometer. The branching fractions are normalized with radiative lifetime measurements to determine the new transition probabilities. Generally good agreement is found between this work and previously reported V ii transition probabilities. Two spectrometers, independent radiometric calibration methods, and independent data analysis routines enable a reduction in systematic uncertainties, in particular those due to optical depth errors. In addition, new hyperfine structure constants are measured for selected levels by least squares fitting line profiles in the FTS spectra. The new V ii data are applied to high resolution visible and UV spectra of the Sun and metal-poor star HD 84937 to determine new, more accurate V abundances. Lines covering a range of wavelength and excitation potential are used to search for non-LTE effects. Very good agreement is found between our new solar photospheric V abundance, log ε(V) = 3.95 from 15 V ii lines, and the solar-system meteoritic value. In HD 84937, we derive [V/H] = −2.08 from 68 lines, leading to a value of [V/Fe] = 0.24.