LEIA discovered an X-ray transient LXT 221227A
ATel #15834; H. Q. Cheng, Z. X. Ling, Y. Liu, C. Zhang, M. J. Liu, C. Z. Cui, D. W. Fan, H. B. Hu, J. W. Hu, M. H. Huang, C. C. Jin, D. Y. Li, J. Q. Li, H. Y. Liu, H. Sun, H. W. Pan, W. X. Wang, Y. L. Wang, Q. Y. Wu, X. P. Xu, Y. F. Xu, H. N. Yang, M. Zhang, W. D. Zhang, D. H. Zhao and W. Yuan (NAOC, CAS), on behalf of the LEIA and Einstein Probe team
on 30 Dec 2022; 02:09 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Yuan Liu (liuyuan@bao.ac.cn)
Subjects: X-ray, Transient
Referred to by ATel #: 15846
LEIA (Lobster Eye Imager for Astronomy), also known as EP-WXT Pathfinder, detected a new X-ray transient, named LXT 221227A, on December 27, 2022. The source position is R.A. = 147.454 deg, DEC = 4.677 deg (J2000), with an uncertainty of 2.2 arcmin (radius, 90% C.L. statistical and systematic). The source was detected at a significance of 5.9 with 14 net photons. Assuming an absorbed power-law model with a photon index of 2.0 and a Galactic absorption of 3.3x10^19 cm^-2, the flux in the 0.5-4.0 keV is 1.8x10^-11 erg/cm^2/s.
No known X-ray sources were found around this position. This position was also covered in two previous observations of LEIA at 2022-12-19T20:33:20 and 2022-12-22T19:30:44. While no X-ray sources were detected within the error circle of LXT 221227A. The preliminary short-term light curve of LXT 221227A shows a possible trend of declining, though with a large uncertainty due to the small number of counts.
Follow-up observations are encouraged to identify this new transient.
LEIA (Zhang et al. 2022, ApJ, 941, 2) is a soft X-ray Lobster-eye imager (0.5 - 4.0 keV) with a FoV of 340 square degrees aboard the SATech-01 satellite of the CAS, launched on July 27, 2022. The above result is preliminary and the final result will be published elsewhere.
