On the centre-to-limb variation and latitude dependence of the asymmetry and wavelength shift of the solar line λ 5576
On the centre-to-limb variation and latitude dependence of the asymmetry and wavelength shift of the solar line λ 5576
复制标题
关于太阳线 λ 5576 的不对称性和波长偏移的中心到肢体变化和纬度依赖性
DOI：
--
复制
发表时间：
1982
期刊：
影响因子：
--
通讯作者：
E. Schröter
中科院分区：
文献类型：
--
作者：
P. Brandt;E. Schröter
报告了 g = 0 Fe 线 gl 5576.097 的线轮廓的低噪声光电测量，并结合使用 I2 吸收管校准的其中心波长偏移的测定。在不同的临边距离 (1.0 ≤ cos ϑ ≤ 0.2) 和沿 4 个不同的太阳直径进行的测量用于研究线不对称性 (C 形) 的行为和线中心的波长偏移作为 cos ϑ 和纬度的函数，并搜索可能的极赤道差异。精度约为 100%。 0.8 mÅ 均方根可以确定太阳线相对于碘线的中心以及 0.3 mÅ 至 1 mÅ r.m.s. C 形的相对变化。分析显示，当 cos ϑ ≤ 0.4 时，沿极地和赤道直径的临边效应曲线与 0.9 ≥ cos ϑ ≥ 0.6 时 C 形的变化之间存在显着差异，并强烈表明 C 形的纬度依赖性。这种纬度依赖性可能解释了霍华德等人观察到的所谓“耳朵”。 (1980)使用了著名的多普勒补偿器方法，该方法整合了从线翼到核心的线不对称性。
Low noise photoelectric measurements of the line profile of the g = 0 Fe line gl 5576.097 combined with determinations of the wavelength shift of its centre calibrated by use of an I2 absorption tube are reported. Measurements taken at various limb distances (1.0 ≤ cos ϑ ≤ 0.2) and along 4 different diameters of the Sun are used to investigate the behaviour of the line asymmetry (C-shape) and wavelength shift of the line centre as functions of cos ϑ and of latitude and to search for possible pole-equator differences.An accuracy of approx. 0.8 mÅ r.m.s. is achieved for the determination of the centre of the solar line relative to the iodine lines and of 0.3 mÅ to 1 mÅ r.m.s. for the relative variations of the C-shape. The analysis shows a significant difference between the limb-effect curves along polar and equatorial diameters for cos ϑ ≤ 0.4 and changes of the C-shape for 0.9 ≥ cos ϑ ≥ 0.6 with a rather strong indication of a latitude dependence of the C-shape. This latitude dependence may account for the so-called ‘ears’ observed by Howard et al. (1980) who used the well-known Doppler compensator method which integrates the line asymmetry from the line wings to the core.