LFBOT ATeL#17646: X-ray upper limit by the Follow-up X-ray Telescope onboard the Einstein Probe
ATel #17651; H. Sun, J. W. Hu, X. Mao (NAO, CAS), Y. L. Hua (PMO, CAS) on behalf of the Einstein Probe team
on 7 Feb 2026; 07:44 UT
Credential Certification: Yuan Liu (liuyuan@bao.ac.cn)
Subjects: X-ray, Transient
We observed the field of the LFBOT candidate reported by Tsuboi et al. (ATel #17646) and followed up by Gill et al. (ATel #17647), Pereyra et al. (ATel #17648) and Schneider et al. (ATel #17649) using the Follow-up X-ray Telescope onboard the Einstein Probe. The observation started at 2026-02-06T18:19:29 (UTC), with an exposure of 5.6 ks. No significant X-ray emission was detected at the position of the LFBOT candidate. Stacking the data of FXT-A and FXT-B modules, we derived a 90% confidence upper limit on the 0.5-10 keV flux of 3e-14 erg/cm^2/s, assuming an absorbed powerlaw spectrum with photon index of 2 and galactic absorption column density of 6.6e20 cm^-2.
Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). EP is a mission of the Chinese Academy of Sciences in collaboration with ESA, MPE and CNES.
