基于时域-空域复合调制傅里叶变换天文光谱成像技术研究

Formation, evolution and activities of stellars and exoplanet searching are hot research topics in astronomy, while these studies are all based on high resolution spectral imaging. However, since the low optical flux and narrow spectral coverage of the conventional dispersive spectrometers, it limits the applications in astronomical observations. Moreover, it is difficult to achieve stellar imaging and spectrum simultaneously. In order to compensate for deficiencies of dispersive spectrometers, this project introduces Fourier transform spectroscopy in astronomical observations to develop Fourier transform astronomical spectroscopy (FTAS) based on time and spatial dual-modulation. This method is able to obviously improve the signal to noise ratio and spectral resolution, so that spectral “data cube” of stellars could be obtained precisely. This research will design and build FTAS based on time and spatial dual-modulation and also realize spectral calibration. Besides, combined with telescope, FTAS will also be applied to detect the spectrums of stellars. The project is aim to achieve astronomical spectrometer with large optical flux, high spectral resolution, wide spectral range, which will provide more effective solutions for astronomical observations.

研究恒星的形成、演化和活动，系外行星系统的搜寻是天文学研究的热点课题，这些研究均建立在高分辨率光谱成像的基础上。然而，传统的色散型光谱仪光通量低，光谱覆盖范围窄，限制了其在天文观测中的应用，且其难以同时实现光谱观测和星体成像。为此，我们将傅里叶变换光谱成像技术引入天文光谱观测中，创新性的发展了基于时域和空域共同调制的傅里叶变换天文光谱成像技术。该方法能在小光学孔径条件下数倍提高天文光谱观测的信噪比和光谱分辨率，从而精确得到被测天体的光谱“数据立方”。本项目将搭建时域-空域复合调制型傅里叶变换光谱成像测量平台，完成成像光谱仪的室内检测与定标，并与小型望远镜对接，最终实现星体的光谱观测。该研究有望实现高通量、高光谱分辨率且同时兼具宽光谱动态范围的光谱成像技术，从而为天文观测提供更为有效的观测手段。