太阳黑子磁场方位角随深度的变化

VARIATION OF THE AZIMUTH OF SUNSPOT MAGNETIC FIELDS WITH DEPTH

为了建立三维的太阳黑子磁场模型,必须确定横向磁场的方位角(X)及其随深度的可能变化.本文提出一种探测x随深度变化的方法,即对黑子内的一定点依次用磁敏谱线的不同部分测量代表线偏振的两个斯托克斯参数Q和U,然后按由牧田贡提出并经我们改进的方法,绘出磁场方位角图.如果x随深度呈现出扭曲结构,则方位角图上的曲线含有圆圈形,否则只是类似抛物线形的较为简单的曲线. 在测量仪器的灵敏度足够的情况下,本方法对黑子外面的日面弱磁场区域也可以使用.

In order to establish the three-dimensional model of sunspot magnetic fields, one has to determine the azimuthal angle of transverse magnetic field (χ) and its possible change with depth. In this paper the following method of probing the variation of χ with depth is proposed. For a fixed point of a sunspot we suggest to measure the Stokes parameters Q and U which represent linear polarization and measurements are made consecutively in various wavelength intervals of a magneto-sensitive spectral line. With such observational data we may draw the figure of magnetic field azimuth originally suggested by Makita and refined by us. If the magnetic field lines are twisted, i.e. if χ varies with depth systematically, then the curve on the above-mentioned diagram exhibit spiral structure. On the contrary, i.e. if χ is constant, we get a comparatively simple curve similar to a parabola. In case of sufficient accuracy of observational facilities our method may be applied also to regions of weak magnetic fields outside sunspots.