First wide field-of-view X-ray observations by a lobster eye focusing telescope in orbit
Creators: name: Zhang, C.
name: Ling, Z. X.
name: Sun, X. J.
name: Sun, S. L.
name: Liu, Y.
name: Li, Z. D.
name: Xue, Y. L.
name: Chen, Y. F.
name: Dai, Y. F.
name: Jia, Z. Q.
name: Liu, H. Y.
name: Zhang, X. F.
name: Zhang, Y. H.
name: Zhang, S. N.
name: Chen, F. S.
name: Cheng, Z. W.
name: Fu, W.
name: Han, Y. X.
name: Li, H.
name: Li, J. F.
name: Li, Y.
name: Liu, P. R.
name: Ma, X. H.
name: Tang, Y. J.
name: Wang, C. B.
name: Xie, R. J.
name: Yan, A. L.
name: Zhang, Q.
name: Jiang, B. W.
name: Jin, G.
name: Li, L. H.
name: Qiu, X. B.
name: Su, D. T.
name: Sun, J. N.
name: Xu, Z.
name: Zhang, S. K.
name: Zhang, Z.
name: Zhang, N.
name: Bi, X. Z.
name: Cai, Z. M.
name: He, J. W.
name: Liu, H. Q.
name: Zhu, X. C.
name: Cheng, H. Q.
name: Cui, C. Z.
name: Fan, D. W.
name: Hu, H. B.
name: Huang, M. H.
name: Jin, C. C.
name: Li, D. Y.
name: Pan, H. W.
name: Wang, W. X.
name: Xu, Y. F.
name: Yang, X.
name: Zhang, B.
name: Zhang, M.
name: Zhang, W. D.
name: Zhao, D. H.
name: Bai, M.
name: Ji, Z.
name: Liu, Y. R.
name: Ma, F. L.
name: Su, J.
name: Tong, J. Z.
name: Wang, Y. S.
name: Zhao, Z. J.
name: Feldman, C.
name: O'Brien, P.
name: Osborne, J. P.
name: Willingale, R.
name: Burwitz, V.
name: Hartner, G.
name: Langmeier, A.
name: Müller, T.
name: Rukdee, S.
name: Schmidt, T.
name: Kuulkers, E.
name: Yuan, W.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: As a novel X-ray focusing technology, lobster eye micro-pore 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 (1979), 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 ($LEIA$), a pathfinder of the wide-field X-ray telescope of the Einstein Probe mission. The piggyback imager, launched in July 2022, has a mostly un-vignetted field of view of $18.6^\circ \times 18.6^\circ $. Its spatial resolution is in the range of 4$-$7 arcmin in FWHM and the focal spot effective area is 2$-$3 cm$^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.
description: 11 pages, 4 figures. Accepted for publication in Astrophysical Journal Letter