Science objectives of the Einstein Probe mission
Weimin Yuan, Li‐Xin Dai, Hua Feng, Chichuan Jin, P. G. Jonker, E. Kuulkers, Yuan Liu, K. Nandra, P. T. O’Brien, L. Piro, A. Rau, N. Rea, J. S. Sanders, Lian Tao, Junfeng Wang, Xuefeng Wu, Bing Zhang, Shuang‐Nan Zhang, Shunke Ai, Johannes Büchner, Esra Bülbül, Hechao Chen, Minghua Chen, Yong Chen, Yupeng Chen, A. Coleiro, F. Coti Zelati, Zi-Gao Dai, Xilong Fan, Zhou Fan, Susanne Friedrich, H. Gao, Changsheng Ge, Mingyu Ge, Jin-Jun Geng, G. Ghirlanda, Giulia Gianfagna, Lijun Gou, Sébastien Guillot, Xian Hou, Jingwei Hu, Yong-Feng Huang, Long Ji, Shumei Jia, S. Komossa, A. K. H. Kong, Lin Lan, An Li, Ang Li, Cheng-Kui Li, Dongyue Li, Jian Li, Zhao-Sheng Li, Zhixing Ling, Ang Liu, Jinzhong Liu, Liang-Duan Liu, Teng Liu, Jiawei Luo, Ruican Ma, P. Maggi, Chandreyee Maitra, A. Marino, Stephen Chi-Yung Ng, Haiwu Pan, Surangkhana Rukdee, Roberto Soria, Hui Sun, Pak-Hin Thomas Tam, Aishwarya Linesh Thakur, Hui Tian, E. Troja, Wei Wang, Xiangyu Wang, Yanan Wang, Junjie Wei, Sixiang Wen, Jianfeng Wu, Ting Wu, Di Xiao, Dong Xu, Renxin Xu, Yan-Jun Xu, Yu Xu, Haonan Yang, Bei You, Heng Yu, Yun-Wei Yu, Binbin Zhang, Chen Zhang, Guobao Zhang, Liang Zhang, Wenda Zhang, Yu Zhang, Ping Zhou, Zecheng Zou
Abstract
Abstract The Einstein Probe (EP) is an interdisciplinary mission of time-domain and X-ray astronomy. Equipped with a wide-field lobster-eye X-ray focusing imager, EP will discover cosmic X-ray transients and monitor the X-ray variability of known sources in 0.5–4 keV, at a combination of detecting sensitivity and cadence that is not accessible to the previous and current wide-field monitoring missions. EP can perform quick characterisation of transients or outbursts with a Wolter-I X-ray telescope onboard. In this paper, the science objectives of the EP mission are presented. EP is expected to enlarge the sample of previously known or predicted but rare types of transients with a wide range of timescales. Among them, fast extragalactic transients will be surveyed systematically in soft X-rays, which include γ -ray bursts and their variants, supernova shock breakouts, and the predicted X-ray transients associated with binary neutron star mergers. EP will detect X-ray tidal disruption events and outbursts from active galactic nuclei, possibly at an early phase of the flares for some. EP will monitor the variability and outbursts of X-rays from white dwarfs, neutron stars and black holes in our and neighbouring galaxies at flux levels fainter than those detectable by the current instruments, and is expected to discover new objects. A large sample of stellar X-ray flares will also be detected and characterised. In the era of multi-messenger astronomy, EP has the potential of detecting the possible X-ray counterparts of gravitational wave events, neutrino sources, and ultra-high energy γ -ray and cosmic ray sources. EP is expected to help advance the studies of extreme objects and phenomena revealed in the dynamic X-ray universe, and their underlying physical processes. Besides EP’s strength in time-domain science, its follow-up telescope, with excellent performance, will also enable advances in many areas of X-ray astronomy.