Ground calibration result of the wide-field X-ray telescope (WXT) onboard the Einstein probe

IF 2.2 3区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Experimental Astronomy Pub Date : 2025-10-04 DOI:10.1007/s10686-025-10025-9

Huaqing Cheng, Chen Zhang, Zhixing Ling, Xiaojin Sun, Shengli Sun, Yuan Liu, Yanfeng Dai, Zhenqing Jia, Haiwu Pan, Wenxin Wang, Donghua Zhao, Yifan Chen, Zhiwei Cheng, Wei Fu, Yixiao Han, Junfei Li, Zhengda Li, Xiaohao Ma, Yulong Xue, Ailiang Yan, Qiang Zhang, Yusa Wang, Xiongtao Yang, Zijian Zhao, Longhui Li, Ge Jin, Weimin Yuan

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引用次数: 0

Abstract

We report on results of the on-ground X-ray calibration of the Wide-field X-ray Telescope (WXT), built from novel lobster-eye micro-pore optics, on board the Einstein Probe (EP) satellite. To fully characterize the performance and properties of the WXT instrument, a series of tests and calibrations were conducted at different levels of devices, assemblies and the complete module before the launch of EP. In this paper, we present the calibration results of three flight model modules (FM1, FM5 and FM11) obtained during their end-to-end module calibration experiments carried out at the 100-m X-ray Test Facility (100XF) of the Institute of High Energy Physics (IHEP), Chinese Academy of Sciences (CAS). Measurements of the Point Spread Function (PSF), effective area, and energy response were performed for multiple incident directions and several characteristic X-ray emission line energies. Specifically, the distributions of the PSF and effective areas are found to be roughly uniform across the FoV, in large agreement with the prediction of lobster-eye optics. Their energy-dependent behavior aligns well with theoretical predictions and Monte Carlo simulations. At \(\sim 1.25\) keV, the full width at half maximum (FWHM) of the focal spot ranges from \(3-7\) arcmin (with a median of \(\sim 4.2\) arcmin) and the effective area is in range of \(\sim 2-3~\mathrm{cm^2}\). Noticeably, the flight model instruments demonstrate a \(\sim 1.5\) arcmin improvement in spatial resolution over the previously launched Lobster Eye Imager for Astronomy. The properties of the complementary metal-oxide semiconductor (CMOS) sensors were also calibrated. The gain coefficients are in range of \(6.4-6.9~\mathrm{eV/DN}\). The energy resolutions are in range of \(\sim 120\) to 140 eV at 1.25 keV, meeting design requirements. These calibration results have been ingested into the first version of calibration database (CALDB) and applied to the analysis of the scientific data acquired by WXT after the launch of EP.

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爱因斯坦探测器上的宽视场x射线望远镜（WXT）地面标定结果

本文报道了爱因斯坦探测器（EP）卫星上采用新型龙虾眼微孔光学技术建造的宽视场x射线望远镜（WXT）的地面x射线校准结果。为了充分表征WXT仪器的性能和特性，在EP启动之前，对不同级别的设备、组件和完整模块进行了一系列测试和校准。本文介绍了在中国科学院高能物理研究所（IHEP） 100米x射线试验台（100XF）进行的3个飞行模型模块（FM1、FM5和FM11）端到端模块校准实验的校准结果。测量了多个入射方向和几个特征x射线发射线能量的点扩展函数（PSF）、有效面积和能量响应。具体来说，PSF和有效面积的分布在整个视场中大致均匀，这与龙虾眼光学的预测在很大程度上一致。它们的能量依赖行为与理论预测和蒙特卡罗模拟很好地吻合。在\(\sim 1.25\) keV处，焦斑半最大值全宽度（FWHM）范围为\(3-7\) arcmin（中值为\(\sim 4.2\) arcmin），有效面积为\(\sim 2-3~\mathrm{cm^2}\)。值得注意的是，飞行模型仪器在空间分辨率上比之前发射的龙虾眼天文成像仪提高了\(\sim 1.5\)弧度。对互补金属氧化物半导体（CMOS）传感器的性能进行了标定。增益系数的范围为\(6.4-6.9~\mathrm{eV/DN}\)。能量分辨率范围为\(\sim 120\)至140 eV (1.25 keV)，满足设计要求。这些校准结果已被纳入第一版校准数据库（CALDB），并应用于EP发射后WXT获取的科学数据分析。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Experimental Astronomy 地学天文-天文与天体物理

CiteScore

5.30

自引率

3.30%

发文量

审稿时长

6-12 weeks

期刊介绍： Many new instruments for observing astronomical objects at a variety of wavelengths have been and are continually being developed. Furthermore, a vast amount of effort is being put into the development of new techniques for data analysis in order to cope with great streams of data collected by these instruments. Experimental Astronomy acts as a medium for the publication of papers of contemporary scientific interest on astrophysical instrumentation and methods necessary for the conduct of astronomy at all wavelength fields. Experimental Astronomy publishes full-length articles, research letters and reviews on developments in detection techniques, instruments, and data analysis and image processing techniques. Occasional special issues are published, giving an in-depth presentation of the instrumentation and/or analysis connected with specific projects, such as satellite experiments or ground-based telescopes, or of specialized techniques.