GCN Circular 42576
Subject
EP251102a: update of EP-FXT follow-up observation
Event
Date
2025-11-04T13:08:10Z (4 days ago)
From
Hao Zhou at Purple Mountain Observatory, CAS <haozhou@pmo.ac.cn>
Via
Web form
H. Zhou, Y.-F. Liang (PMO, CAS) and H.-W. Pan (NAO, CAS) report on behalf of the Einstein Probe team:
The Follow-up X-ray Telescope (FXT) on board the Einstein Probe (EP) performed one ToO observation for EP251102a, starting at 2025-11-03T11:21:51 (UTC) with an exposure time of about 2.1 ks. The ground-processed position of EP251102a is R.A. = 113.1622 deg, DEC = 7.3217 deg (J2000) with an uncertainty of 10 arcsec in radius (90% C.L. statistical and systematic). The updated position is consistent with the counterpart reported before (Schneider et al. GCN 42544, Eyles-Ferris et al. GCN 42546, Liang et al. GCN 42548, Adami et al. GCN 42575).
The average FXT 0.5-10 keV spectrum can be fitted with an absorbed power law with a fixed Galactic hydrogen column density of 9.1 x 10^20 cm^-2 and a photon index of 1.93+/-0.36. The derived average unabsorbed 0.5-10 keV flux is (4.8+/-1.3) x 10^(-13) erg/s/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).