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  • 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.


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  • 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 1   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)



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