First Wide Field-of-view X-Ray Observations by a Lobster-eye Focusing Telescope in Orbit
C. Zhang, Z. X. Ling, Xiujun Sun, S. L. Sun, Yu Liu, Zilong Li, Yun‐Shan Xue, Y. F. Chen, Y. F. Dai, Zhiyan Jia, He‐Yang Liu, Xue Zhang, Yuheng Zhang, Shuang‐Nan Zhang, Feng Chen, Zhengwei Cheng, Wen Fu, Y. X. Han, Hui Li, J. F. Li, Yifan Li, P. R. Liu, Xinhua Ma, Yanjun Tang, Chuxuan Wang, Ronghuan Xie, A. L. Yan, Qizhou Zhang, Bingrun Jiang, Ge Jin, Longhui Li, Xintao Qiu, D. T. Su, Jianning Sun, Zijian Xu, S. K. Zhang, Zhaoyi Zhang, Na Zhang, Xupeng Bi, Zhengyang Cai, Junjun He, Haiqing Liu, Xiaobo Zhu, Haiyang Cheng, Chenzhou Cui, Dongwei Fan, H. B. Hu, Min Huang, Chichuan Jin, Dongyue Li, Haiwu Pan, W. X. Wang, Yunfei Xu, X. Yang, Banglin Zhang, Mei Zhang, Wenda Zhang, Donghua Zhao, Miaomiao Bai, Zhuoyu Ji, Yan-Rui Liu, F. L., Jingzhi Su, Jingjing Tong, Yutao Wang, Zijian Zhao, C. Feldman, P. T. O’Brien, J. P. Osborne, R. Willingale, V. Burwitz, Gisela Hartner, Andreas Langmeier, T. Müller, Surangkhana Rukdee, Thomas Schmidt, E. Kuulkers, Wei Yuan
Abstract
Abstract As a novel X-ray focusing technology, lobster-eye micropore optics (MPO) feature both a wide observing field of view and true imaging capability, promising sky monitoring with significantly improved sensitivity and spatial resolution in soft X-rays. Since first proposed by Angel, the optics have been extensively studied, developed and trialed over the past decades. In this Letter, we report on the first-light results from a flight experiment of the Lobster Eye Imager for Astronomy, a pathfinder of the wide-field X-ray telescope of the Einstein Probe mission. The piggyback imager, launched in 2022 July, has a mostly unvignetted field of view of 18.°6 × 18.°6. Its spatial resolution is in the range of 4′–7′ in FWHM and the focal spot effective area is 2–3 cm 2 , both showing only mild fluctuations across the field of view. We present images of the Galactic center region, Sco X-1, and the diffuse Cygnus Loop nebular taken in snapshot observations over 0.5–4 keV. These are truly wide-field X-ray images of celestial bodies observed, for the first time, by a focusing imaging telescope. Initial analyses of the in-flight data show excellent agreement between the observed images and the on-ground calibration and simulations. The instrument and its characterization are briefly described, as well as the flight experiment. The results provide a solid basis for the development of the present and proposed wide-field X-ray missions using lobster-eye MPO.