More info
  • ReceivedOct 27, 2017
  • AcceptedJan 4, 2018
  • PublishedJan 26, 2018
PACS numbers


The Einstein Probe is a small mission dedicated to time-domain astronomy to monitor the sky in the soft X-ray band(0.5–4 keV). It will carry out systematic survey and characterisation of high-energy transients at unprecedented sensitivity, spatial resolution, Grasp and monitoring cadence. Its wide-field imaging capability, as provided by an X-ray monitor with a field of view of 3600 square degrees, is enabled by using established technology of micro-pore lobster-eye focusing optics. Complementary to this wide-field instrument is a follow-up X-ray telescope with a large effective area and a narrow field of view. It is also capable of real time triggering and downlink of transient alerts on the fly, in order to activate multi-wavelength follow-up observations by other astronomical facilities worldwide. Its scientific goals are concerned with discovering new or rare types of transients, particularly tidal disruption events, supernova shock breakouts, high-redshift gamma-ray bursts and, particularly, electromagnetic sources associated with gravitational wave events. The mission is planned for launch around end of 2022, with a lifetime of three years and five years as a goal.

Funded by



由于篇幅有限, 未能列出EP项目团队各个单位的所有参与人员, 在此一并表示感谢. 对长期以来对EP项目予以支持、帮助与合作的同事表示衷心的感谢. 感谢郝晋新、张晓宇、包聪颖、曹丽、王慎、胡景耀、马玉倩、薛随建、陶鹏、韦飞、范全林、曹松、任丽文、孙丽琳、郑建华、朱振才、陈雯、余金培、魏建彦、李晔、姚苏、杨雪、常进、王挺贵、周宏岩、R. Willingale, P. O’Brien, J. P. Osborne, M. Matsuoka, N. Gehrels, G. Fraser, B. Cordier, T. Mihara, S. Komossa, M. Feroci, L. Piro等人. 感谢与EP科学工作组成员的广泛而深入的讨论.


[1] Abbott B P, Abbott R, Abbott T D, et al. Observation of gravitational waves from a binary black hole merger. Phys Rev Lett, 2016, 116: 061102 CrossRef PubMed ADS arXiv Google Scholar

[2] Abbott B P, Abbott R, Abbott T D, et al. GW151226: Observation of gravitational waves from a 22-solar-mass binary black hole coalescence. Phys Rev Lett, 2016, 116: 241103 CrossRef PubMed ADS arXiv Google Scholar

[3] Abbott B P, Abbott R, Abbott T D, et al. GW170817: Observation of gravitational waves from a binary neutron star inspiral. Phys Rev Lett, 2017, 119: 161101 CrossRef PubMed Google Scholar

[4] Gehrels N, Chincarini G, Giommi P, et al. The Swift gamma-ray burst mission. Astrophys J, 2004, 611: 1005-1020 CrossRef ADS Google Scholar

[5] Matsuoka M, Kawasaki K, Ueno S, et al. The MAXI mission on the ISS: Science and instruments for monitoring all-sky X-ray images. Publ Astron Soc Jpn, 2009, 61: 999-1010 CrossRef ADS arXiv Google Scholar

[6] Gehrels N, Cannizzo J K. How Swift is redefining time domain astronomy. J High Energy Astrophys, 2015, 7: 2-11 CrossRef ADS arXiv Google Scholar

[7] Gehrels N, Barthelmy S D, Cannizzo J K. Time domain astronomy with Swift, Fermi and Lobster. In: Proceedings of the International Astronomical Union, 2011. Google Scholar

[8] Yuan W, Osborne J P, Zhang C, et al. Exploring the dynamic X-ray universe: Scientific opportunities for the Einstein Probe mission. Chin J Space Sci, 2016, 36: 117-138 CrossRef Google Scholar

[9] Yuan W, Amati L, Cannizzo J K, et al. Perspectives on gamma-ray burst physics and cosmology with next generation facilities. Space Sci Rev, 2016, 202: 235-277 CrossRef ADS arXiv Google Scholar

[10] Holt S S, Priedhorsky W. All-sky monitors for X-ray astronomy. Space Sci Rev, 1987, 45: 269-289 CrossRef ADS Google Scholar

[11] Yuan W, Zhang C, Feng H, et al. Einstein Probe-A small mission to monitor and explore the dynamic X-ray universe. In: Proceedings of Swift: 10 Years of Discovery, Rome, 2015. Google Scholar

[12] Rees M J. Tidal disruption of stars by black holes of 106–108 solar masses in nearby galaxies. Nature, 1988, 333: 523-528 CrossRef ADS Google Scholar

[13] Komossa S, Bade N. The giant X-ray outbursts in NGC 5905 and IC 3599: Follow-up observations and outburst scenarios. Astrophys, 1999, 343: 775–787, arXiv: astro-ph/9901141. Google Scholar

[14] Komossa S. Tidal disruption of stars by supermassive black holes: Status of observations. J High Energy Astrophys, 2015, 7: 148-157 CrossRef ADS arXiv Google Scholar

[15] Burrows D N, Kennea J A, Ghisellini G, et al. Relativistic jet activity from the tidal disruption of a star by a massive black hole. Nature, 2011, 476: 421-424 CrossRef PubMed ADS arXiv Google Scholar

[16] Liu F K, Li S, Komossa S. A milliparsec supermassive black hole binary candidate in the galaxy SDSS J120136.02+300305.5. Astrophys J, 2013, 786: 103-117 CrossRef ADS arXiv Google Scholar

[17] Liu Z, Yuan W M, Sun H, et al. Massive black holes and tidal disruption events at the center of galaxies (in Chinese). Sci Sin-Phys Mech Astron, 2018, 48: 039503 CrossRef Google Scholar

[18] Remillard R A, McClintock J E. X-ray properties of black-hole binaries. Annu Rev Astron Astrophys, 2006, 44: 49-92 CrossRef ADS Google Scholar

[19] Negoro H, et al. (MAXI team). Discovery of 17 X-ray transients with MAXI/GSC and their nature. In: Proceedings of 7 Years of MAXI Monitoring X-ray Transients, Saitama, 2017. 15–20. Google Scholar

[20] Feng H, Soria R. Ultraluminous X-ray sources in the Chandra and XMM-Newton era. New Astron Rev, 2011, 55: 166-183 CrossRef ADS arXiv Google Scholar

[21] Middleton M J, Miller-Jones J C A, Markoff S, et al. Bright radio emission from an ultraluminous stellar-mass microquasar in M 31. Nature, 2013, 493: 187-190 CrossRef PubMed ADS arXiv Google Scholar

[22] Sippel A C, Hurley J R. Multiple stellar-mass black holes in globular clusters: Theoretical confirmation. Mon Not R Astron Soc, 2013, 430: L30-L34 CrossRef ADS arXiv Google Scholar

[23] Gehrels N, Sarazin C L, O’Brien P T, et al. A short γ-ray burst apparently associated with an elliptical galaxy at redshift z=0.225. Nature, 2005, 437: 851-854 CrossRef PubMed ADS Google Scholar

[24] Li L X, Paczyński B. Transient events from neutron star mergers. Astrophys J, 1998, 507: L59-L62 CrossRef ADS Google Scholar

[25] Fan X L, Hendry M. Multimessenger astronomy. Physics, 2015, 18: 1591–1595, arXiv: 1509.06022. Google Scholar

[26] Schutz B F. Determining the Hubble constant from gravitational wave observations. Nature, 1986, 323: 310-311 CrossRef ADS Google Scholar

[27] Nissanke S, Kasliwal M, Georgieva A. Identifying elusive electromagnetic counterparts to gravitational wave mergers: An end-to-end simulation. Astrophys J, 2013, 767: 124 CrossRef ADS arXiv Google Scholar

[28] Zhang B. Early X-ray and optical afterglow of gravitational wave bursts from mergers of binary neutron stars. Astrophys J, 2013, 763: L22 CrossRef ADS arXiv Google Scholar

[29] Sun H, Zhang B, Gao H. X-ray counterpart of gravitational waves due to binary neutron star mergers: Light curves, luminosity function, and event rate density. Astrophys J, 2017, 835: 7 CrossRef ADS arXiv Google Scholar

[30] Gao H, Fan X L, Wu X F, et al. Detection of electromagnetic counterpart for gravitational wave bursts (in Chinese). Sci Sin-Phys Mech Astron, 2018, 48: 039504 CrossRef Google Scholar

[31] Soderberg A M, Berger E, Page K L, et al. An extremely luminous X-ray outburst at the birth of a supernova. Nature, 2008, 453: 469-474 CrossRef PubMed ADS arXiv Google Scholar

[32] Deng J S, Wang X Y. On the detection of shock breakouts of core-collapse supernovae with the Einstein Probe satellite (in Chinese). Sci Sin-Phys Mech Astron, 2018, 48: 039506 CrossRef Google Scholar

[33] Bromm V, Loeb A. High-redshift gamma-ray bursts from population III progenitors. Astrophys J, 2006, 642: 382-388 CrossRef ADS Google Scholar

[34] Ciardi B, Loeb A. Expected number and flux distribution of gamma-ray burst afterglows with high redshifts. Astrophys J, 2000, 540: 687-696 CrossRef ADS Google Scholar

[35] Butler N R, Bloom J S, Poznanski D. The cosmic rate, luminosity function, and intrinsic correlations of long gamma-ray bursts. Astrophys J, 2010, 711: 495-516 CrossRef ADS arXiv Google Scholar

[36] Wei J J, Wu X F, Wang F Y, et al. High redshift gamma-ray bursts as a probe of the early universe and first stars (in Chinese). Sci Sin-Phys Mech Astron, 2018, 48: 039505 CrossRef Google Scholar

[37] Li B, Sun H, Wang L J, et al. Special gamma-ray bursts and special radiation components from gamma-ray bursts (in Chinese). Sci Sin-Phys Mech Astron, 2018, 48: 039507 CrossRef Google Scholar

[38] Kaneko Y, Ramirez-Ruiz E, Granot J, et al. Prompt and afterglow emission properties of gamma-ray bursts with spectroscopically identified supernovae. Astrophys J, 2007, 654: 385-402 CrossRef ADS Google Scholar

[39] Levan A J, Tanvir N R, Starling R L C, et al. A new population of ultra-long duration gamma-ray bursts. Astrophys J, 2014, 781: 13-34 CrossRef ADS arXiv Google Scholar

[40] Hu Y D, Liang E W, Xi S Q, et al. Internal energy dissipation of gamma-ray bursts observed with Swift: Precursors, prompt gamma-rays, extended emission, and late X-ray flares. Astrophys J, 2014, 789: 145-157 CrossRef ADS arXiv Google Scholar

[41] Heise J, Zand J, Kippen M, et al. X-ray flashes and X-ray rich gamma ray bursts. In: Gamma-Ray Bursts in the Afterglow Era. Heidelberg: Springer, 2001. 16–21. Google Scholar

[42] Olausen S A, Kaspi V M. The mcgill magnetar catalog. Astrophys J, 2014, 212: 6 CrossRef ADS arXiv Google Scholar

[43] Wang Z X, Xu R X, Li X D, et al. Detecting magnetars with Einstein Probe (in Chinese). Sci Sin-Phys Mech Astron, 2018, 48: 039510 CrossRef Google Scholar

[44] Pretorius M L, Knigge C. The space density and X-ray luminosity function of non-magnetic cataclysmic variables. Mon Not R Astron Soc, 2012, 419: 1442-1454 CrossRef ADS arXiv Google Scholar

[45] Xu X J. Einstein Probe: Application on the observation of cataclysmic variables (in Chinese). Sci Sin-Phys Mech Astron, 2018, 48: 039511 CrossRef Google Scholar

[46] Mushotzky R F, Done C, Pounds K A. X-Ray spectra and time variability of active galactic nuclei. Annu Rev Astron Astrophys, 1993, 31: 717-761 CrossRef Google Scholar

[47] McHardy I M, Koerding E, Knigge C, et al. Active galactic nuclei as scaled-up Galactic black holes. Nature, 2006, 444: 730-732 CrossRef PubMed ADS Google Scholar

[48] Yuan W, Komossa S, Xu D, et al. Discovery of high-amplitude X-ray variability in the Seyfert-LINER transition galaxy NGC 7589. Mon Not R Astron Soc, 2004, 353: L29-L33 CrossRef ADS Google Scholar

[49] Xue Y Q, Shu X W, Zhou X L, et al. Einstein Probe’s scientific opportunities in the field of active galactic nuclei (in Chinese). Sci Sin-Phys Mech Astron, 2018, 48: 039508 CrossRef Google Scholar

[50] Gou L J, Dong Y T, Wang Z X, et al. The X-ray binary system in the EP era (in Chinese). Sci Sin-Phys Mech Astron, 2018, 48: 039509 [苟利军, 董燕婷, 王仲翔等. X射线双星系统的探测. 中国科学: 物理学 力学 天文学, 2018, 48: 039509]. Google Scholar

[51] Angel J R P. Lobster eyes as X-ray telescopes. Astrophys J, 1979, 233: 364–373. Google Scholar

[52] Fraser G W, Carpenter J D, Rothery D A, et al. The mercury imaging X-ray spectrometer (MIXS) on bepicolombo. Planet Space Sci, 2010, 58: 79-95 CrossRef ADS Google Scholar

[53] Zhao D, Zhang C, Yuan W, et al. Geant4 simulations of a wide-angle X-ray focusing telescope. Exp Astron, 2017, 43: 267-283 CrossRef ADS arXiv Google Scholar

  • Figure 1

    Illustration of light paths of focusing imaging for a point-like source by a lobster-eye MPO optics (the pores of commonly used plates have a size of the order of 20 μm).

  • Figure 2

    (a) A demonstration prototype of a lobster-eye MPO mirror assembly (developed at X-ray Imaging Lab, NAOC); (b) an X-ray image formed on its focal plane for a point-like source showing the characteristic cruciform PSF of the lobster-eye optics (credit: XIL, NAOC).

  • Figure 3

    Design of one module of the wide-field X-ray telescope (WXT), consisting mainly of an optical baffle, MPO plates and focal plane detectors (credit: XIL, NAOC).

  • Figure 4

    Illustration of the field-of-views of WXT modules and FXT.

  • Figure 5

    Preliminary design of the follow-up X-ray telescope FXT.

  • Figure 6

    A possible configuration of the EP payload, with twelve WXT modules and the FXT telescope at the centre (credit: MicroSAT).

  • Figure 7

    Simulated effective area curves of WXT for the central focal spot and plus the cruciform arms. The MPO arrays are coated with iridium. The focal plane detectors are back-illuminated CMOSs (layer thickness of 20 μm and the surface is coated with 200 nm-thick aluminum).

  • Figure 8

    Grasp of EP/WXT (effective area times field of view) and comparison with the current and future missions with focusing X-ray optics.

  • Figure 9

    Profile of the simulated point-spread-function of WXT of the central spot on the focal plane. The PSF is ~5′ (FWHM).

  • Figure 10

    Simulated X-ray sky image of 400 squ.deg. observed by WXT with an accumulated exposure of 10 ks (based on the ROSAT All-sky Survey catalogue).

  • Figure 11

    Simulated background on the detector of WXT in orbit, including the incident diffuse X-ray emission and background generated by charged particles in space (see Figure 7 caption for the specification of the CMOS detectors).

  • Figure 12

    Detection limiting fluxes (sensitivity) of WXT and its dependence on accumulative exposure time for cosmic X-ray sources with typical spectral shape (power-law photon index of −2 and −3, respectively, assuming a Galactic ISM absorption column density 3×1020 cm−2). The shaded area indicates the typical sensitivity of the ROSAT All-sky Survey.

  • Figure 13

    Illustration of the survey mode of EP in orbit as a series of (currently three) pointed observations for ~20 min exposure each. EP can cover the entire night sky (anti-solar direction) in three consecutive orbits (credit: MicroSAT).

  • Figure 14

    Distribution of the accumulated exposure time of WXT in the sky for one-day operation (credit: MicroSAT).

  • Figure 15

    Distribution of the number of observations with WXT in the sky for one-day operation (credit: MicroSAT).

  • Figure 16

    Illustration of the system in operation of the EP mission.

  • Table   Specifications of WXT and FXT








    3600 sq.deg.





    能段 (keV)



    能量分辨@1 keV (eV)



    有效面积@1 keV (cm2)



Copyright 2019 Science China Press Co., Ltd. 《中国科学》杂志社有限责任公司 版权所有