Study on Dynamical Structure of Stellar Atmosphere on the Basis of High Precision Spectroscopy

为了阐明恒星大气的动力学结构，需要对恒星光谱中的谱线进行高精度的测量。为此，高信噪比和高光谱分辨率的高质量光谱观测必不可少。在本项目中，我们将15微米像素的高分辨率CCD探测器RCA006引入到已经在冈山天体物理天文台使用的PSI CCD V系统中。为此，还设计了一种具有改进温度控制功能的新型杜尔。经过测试，该系统达到了预期的高分辨率，读出噪声也很低。利用该系统在冈山天体物理观测站进行了近焦天文观测，结果表明，该系统在8000A左右的近红外波段表现良好。此外，还开发了一种新的CCD光谱分析软件，以简化数据处理。证实了可以高精度地测量CaII红外三重态这类强谱线的谱线和强度，并且可以很好地解析TiO等分子旋转结构的复杂精细结构。为了阐明恒星外层的动力学结构，对这些光谱的进一步分析正在进行中。

To clarify the dynamical structure of stellar atmosphere, it is necessary to measure line profile in stellar spectra with high precision. For this purpose, spectroscopic observations of high quality with high S/N ratio a high spectral resolution should be indispensable. In the present project, we introduce high resolution CCD detector RCA006 with 15 micron pixel size int the PSI CCD V system which is already in use at Okayama Astrophysical Observatory. For this purpose, a new Dewer with improved temperature control is also designed. The system is test and found to be excellent in that expected high resolution has been attained and readout noise turned out to be pretty low. With this new system, astronomical observations at coude focus at Okayama Astrophysical Observatory is done and the performance is found to be fine especially in the near infrared around 8000A. Also, a new software to analyse the CCD spectra has been developed to facilitate the data reduction. It is confirmed that the profile as well as intensity of such strong lines as CaII IR triplet could be measured with high precision and complicated fine structure of the rotational structure of such molecule as TiO could be well resolved. Further analyses on these spectra to clarify the dynamical structure of stellar outer layer are under way.