We have obtained theoretical calibration curves to convert the amount of polarization into the strength of magnetic field, by a numerical calculation of radiation transfer for the polarized spectral line of FeI 6303\AA. In our calculation, three kinds of atmospheric models (VAL-C, penumbra, umbra) have been used to make a proper calibration for an active region composed of quiet, penumbral and umbral areas. It was found that firstly, the results of our calculation depend highly on a kind of atmospheric model rather than on any other input parameters used in a model. Secondly, observed line profile showed m solar spectrum atlas proved to be very similar to the calculated profiles obtained by using a penumbra model. Finally, another method except this calibration curve should be developed to estimate correctly the distribution of magnetic field in solar active region from the observation of polarized spectral line.

• 김갑성(경희대학교 우주과학과, 경희천문대, 경희대학교 자연과학 종합 연구원) | Kim Kap-Sung (Department of Astronomy & Space Science, Kyung Hee Astronomical Observatory, Institute of Natural Sciences, Kyung Hee University)