中国科学院云南天文台机构知识库

主要介绍了抚仙湖1 m新真空太阳望远镜(the 1-meter New Vacuum Solar Telescope,NVST)6 m水平式近红外光谱仪的安装过程和实测结果。主要讨论内容是光路设计特点、光学系统的装调以及利用该光谱仪对活动区NOAA 11662黑子进行的初步近红外光谱实测(波长1.56μm附近)。成功观测到由黑子强磁场造成的Fe I 1.56μm谱线裂变现象,并初步估算了磁场强度。该光谱的成功装调和使用,充分实现了对9 m光谱仪光学系统的整体检测,为9 m光谱仪的安装调试提供了宝贵的经验和参考。

This paper first presents the design, layout, and installation of a near-infrared grating spectrograph installed on the 1m new vacuum solar telescope in the Fuxian-Lake Solar-Observation Station of the Yunnan Observatories. It records spectra in the wavelength range of 1.0μm-2.0μm. The focal length of its collimating mirror is 6m and its spectral resolution can reach about 6x 10~(-6)μm/pixel. Using this spectrograph and a previously built near-infrared detector (with an InGaAs detector of 512x640 pixels and a pixel size of 25 μm) we can obtain solar spectra with a wavelength coverage of 0. 004μm. One purpose of making this horizontal-type spectrograph is to evaluate main designs to be used in the vertical-type 9m near-infrared spectrograph in future. The designs include those of the Echelle grating, infrared detector, and infrared front-filter. With the spectrograph we can also accumulate experience of observing near-infrared solar spectra, particularly, in setting the slit width, exposure time, and wavelength calibration. Using the spectrograph we successfully observed a sunspot region in a wavelength range around 1.565 μm. This range covers two commonly studied spectral lines (Fe I 1.5648μm and Fe I 1.5653μm),which are sensitive to solar magnetic-field strengths. We reduced the data using codes designed for the 1m telescope. The wavelength calibration is based on the standard solar spectrum. We calculated the magnetic-field strength (instead of the magnetic-field flux) from the line split rather straightforwardly. These preliminary results demonstrate the effectiveness of this 6m spectrograph in achieving its scientific goals.