硬X射线调制望远镜对银道面X射线辐射的成像探测研究

Hard X-ray Modulation Telescope (HXMT) is dedicated to detect a large number of X-ray transients, the Galactic ridge structure and large scale X-ray potential emission through its Galactic scanning observation. Image reconstruction is necessary in converting the scanning observed data into scientific data, thus is of great importance for the realization of the scientific goal. This project will focus on the image reconstruction methods, and aims to develop a set of tools to analyse the scanning data, covering data pre-processing, background estimation, reconstruction, evaluation, etc. Modification and optimization have been made for some reconstruction methods, and a fast algorithm for calculating the significance of the reconstructed sources has been proposed. According to a comprehensive study with the current configuration of HXMT, an optimal image reconstruction scheme will be suggested, which will improves the detection performance of HXMT and will be tested and optimized with its in-obit data. The algorithms and methods proposed in this project are also fit for other astronomical imaging systems, thus can be used to improve the quality of image reconstruction in other fields of astronomy.

硬X射线调制望远镜（HXMT）的银道面扫描旨在发现新的X射线瞬变源、还原银河系的脊状结构和发现潜在的大尺度弥散辐射。图像重建是将HXMT扫描数据转成科学数据的必要环节，是关系到其科学目标能否实现的重要因素。本项目针对HXMT扫描数据的图像重建展开研究，拟开发和完善一套扫描数据重建工具，包括数据预处理、本底的估计和处理、重建算法的选择、重建结果的量化评价等研究环节。目前，我们已经对一些重建算法进行了改进和优化，提出了重建图像的显著性的快速估计方法。本项目将利用HXMT的模拟扫描数据来进行研究，给出HXMT扫描数据的最佳重建方案，提高HXMT成像探测能力。并利用在轨数据进一步检验和优化算法，进一步提高HXMT的探测性能。本项目提出的图像重建方法也适用于一般天文成像系统，可用于提高一般天文图像的重建质量。

硬X射线调制望远镜（Insight-HXMT）的银道面扫描旨在发现新的X射线瞬变源、监测已知源和探测银河系的大尺度弥散辐射。图像重建是将Insight-HXMT扫描数据转成科学数据的必要环节，是关系到其科学目标能否实现的重要因素。本项目开发了Insight-HXMT银道面扫描数据处理的软件包，实现了对扫描数据的自动化处理。通过分析Insight-HXMT在轨三年多的扫描观测数据，给出了含2000余个源的源表，并获得每个源的长期流量监测曲线；发现一批疑似源；绘制了银道面弥散X射线背景辐射天图；获得了三个载荷在单次快速扫描观测下的灵敏度（LE: 5 mCrab、ME: 20 mCrab、HE: 18 mCrab）。此外，通过对直接解调算法进行改进，发展出适用于短时标变源重建的含时直接解调方法，可以用来搜寻超大快速X射线瞬变源这类重要天体。本项目的研究成果可以为我国未来X射线天文卫星的数据处理积累经验。