日珥谱线不对称性的研究 Ⅰ.视向速度对谱线轮廓的影响

本文主要从理论上用解析方法讨论日珥视向速度随深度变化对谱线轮廓对称性的影响,得到的结论具有普遍性。第二节的分析表明,日珥的谱线轮廓可表示为二项叠加,其中第一项与源函数无关,只依赖于速度场模型,源函数分布仅通过第二项对谱线轮廓产生影响。然后在源函数不随深度变化的假定下,讨论各种速度场模型的谱线轮廓是否对称。得到的结论为:(1)常源函数与常速度场结合的谱线轮廓为对称轮廓;(2)常源函数与线性对称速度场结合的谱线也是对称轮廓;(3)常源函数与线性非对称速度场结合的谱线轮廓为不对称轮廓。最后,用数值计算对理论分析结果进行了检验。

AN INVESTIGATION ON THE SYMMETRY OF THE LINE PROFILE OF A SOLAR PROMINENCE I. THE EFFECTS OF THE LINE OF SIGHT VELOCITY ON THE LINE PROFILE

This paper is a theoretical analytic investigation of the line profile of a prominence affected by the line of sight velocity. Thus the conclusions are of universal significance. The analysis in section two of the paper shows clearly that the line profile of a prominence can be represented by two terms. One of the terms depends only on the model of the velocity distribution, and is independent of the source function. The other term evaluates the effect of the distribution of the source function upon the line profile. Assumming that the source function is constant, we discussed whether the line profile is symmetrical or not using some models of the velocity distribution. The results are: (1) The line profile is symmetrical for constant velocity distribution; (2) The line profile is also symmetrical for symmetrically linear Velocity distribution; (3) The line profile is asymmetrical for asymmetrically linear velocity distribution. At the end of the paper, it is shown that the results of the theoretical analysis were verified by our numerical calculation.