GCN Circular 38513
Subject
EP241208a: EP-FXT follow-up observations
Date
2024-12-10T06:17:47Z (a month ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
Y. Wang (PMO, CAS), Y. L. Wang (NAO, CAS), H. L. Peng (NNU), W. D. Zhang (NAO,CAS) report on behalf of the Einstein Probe team:
Following the detection of the fast X-ray transient EP241208a (Wang et al., GCN 38477), we performed an observation with the Follow-up X-ray Telescope (FXT) on board the Einstein Probe mission. The observation started at 2024-12-09 14:46:02 (UTC), about 22 hours after the EP-WXT detection, with an exposure time of 3.7 ks. Within the WXT error circle, an uncatalogued X-ray source is detected at R.A. = 127.8303 deg, DEC = 49.0831 deg (J2000) with an uncertainty of 10 arcsec in radius (90% C.L. statistical and systematic). The average FXT spectrum in 0.5-10 keV can be fitted by an absorbed power law with a photon index of 2.85(+0.64/-0.58) and the column density fixed at the Galactic value of 4.20 x 10^20 cm^-2, giving an average unabsorbed flux of 1.03(+0.34/-0.24) x 10^-13 erg/s/cm^2 in the 0.5-10 keV band. It is noted that a galaxy, SDSS J083120.19+490500.1, with a redshift of z ~ 0.5, is located at approximately 9 arcsec from the FXT position.
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).