TITLE:   GCN CIRCULAR
NUMBER:  44086
SUBJECT: GRB 260321A: EP-FXT follow-up observation
DATE:    26/03/23 03:51:16 GMT
FROM:    EP Team at NAOC/CAS <ep_ta@bao.ac.cn>

Z.-C. Zou, Y. H. Jiang (NJU), J. P. Chen (SYSY), Y. J. Yi (BNU), W. D. Zhang (NAOC, CAS) on behalf of the Einstein Probe (EP) team:

EP-FXT performed a follow-up observation of the SVOM/ECLAIRs-detected burst GRB 260321A (SVOM/sb26032123; Brunet et al., GCN 44071) starting at 2026-03-22T15:23:32 UTC, approximately 21 hours after the SVOM trigger, with a total exposure time of 4565 s. Four uncataloged sources are detected within the ECLAIRs error circle. Preliminary analysis on these sources is automatically conducted, and the details are listed as follows.

EPF_J143847.8+314542
RA (J2000): 219.6990
Dec (J2000): 31.7616
Flux: 9.265 x 10^-14 erg/s/cm2 (observed, 0.5-10 keV)
Flux_err: 3.498 x 10^-14 erg/s/cm2 (1 sigma)

EPF_J143759.7+314425
RA (J2000): 219.4989
Dec (J2000): 31.7404
Flux: 2.9252 x 10^-14 erg/s/cm2 (observed, 0.5-10 keV)
Flux_err: 1.2651 x 10^-14 erg/s/cm2 (1 sigma)

EPF_J143833.9+314628
RA (J2000): 219.6440
Dec (J2000): 31.7719
Flux: 5.9349 x 10^-14 erg/s/cm2 (observed, 0.5-10 keV)
Flux_err: 2.0193 x 10^-14 erg/s/cm2 (1 sigma)

EPF_J143845.7+313613
RA (J2000): 219.6902
Dec (J2000): 31.6037
Flux: 8.0698 x 10^-14 erg/s/cm2 (observed, 0.5-10 keV)
Flux_err: 1.9625 x 10^-14 erg/s/cm2 (1 sigma)

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).