{
  "body": "D. Turpin (CEA), H. Q. Cheng, W. Xie (NAOC, CAS), Y. F. Liang (PMO, CAS), J. Q. Peng (IHEP, CAS), W. Yuan (NAOC, CAS), S. Guillot (IRAP), J. Guan, C. K. Li, Y. Chen, S. M. Jia, W. W. Cui, D. W. Han, W. Li, C. Z. Liu, F. J. Lu, L. M. Song, J. Wang, J. J. Xu, J. Zhang, S. N. Zhang, H. S. Zhao, X. F. Zhao (IHEP, CAS), H. Sun, Y. Liu, C. C. Jin, C. Zhang, J. Wang, L. P. Xin (NAOC, CAS), E. Kuulkers, A. Santovincenzo (ESA), P. O'Brien (Univ. of Leicester), K. Nandra, A. Rau (MPE), B. Cordier (CEA) on behalf of the SVOM and Einstein Probe teams\n\nWe performed a follow-up observation of GRB 240821A (detected by SVOM/ECLAIRs Cangemi et al, GCN 37220; SVOM/GRM He et al. GCN 37226 and Fermi/GBM GCN 37219) with the Follow-up X-ray Telescope (FXT) on board the Einstein Probe (EP) mission. The observation began at 2024-08-22T03:22:05 (T-TGRB ~ 9 hrs), and the exposure time is about 3.0 ks. FXT-A detected 2 uncatalogued sources in the 90% localization error circle provided by SVOM/ECLAIRs (with a radius of 13 arcmin centered at RA, DEC = 354.23 deg, -10.18 deg), and 7 are detected by FXT-B.\n\nThe following table lists the detailed information of the X-ray sources detected by FXT-A and FXT-B. The positions are given with an uncertainty of 10 arcsec (radius, 90% C.L. statistical and systematic). The uncertainties of flux are at the 90% confidence level.\n\nFXT-A candidate list: \nSource name         | RA       |  DEC     | Estimated Flux       | SNR | Dist from SVOM/ECLAIRs |\n                    | deg      |  deg     | (erg/s/cm^2)         |     | offset (in arcmin)     |\n-------------------------------------------------------------------------------------------------\nEP J233704.9-101126 | 354.2703 | -10.1905 | 1.3(+/-0.3) x 10^-13 | 7.6 |          2.46          | \nEP J233641.3-100257 | 354.1720 | -10.0491 | 5.5(+/-2.2) x 10^-14 | 4.2 |          8.57          | \n-------------------------------------------------------------------------------------------------\n\nFXT-B candidate list: \nSource name         | RA       |  DEC     | Estimated Flux       | SNR | Dist from SVOM/ECLAIRs |\n                    | deg      |  deg     | (erg/s/cm^2)         |     | offset (in arcmin)     |\n-------------------------------------------------------------------------------------------------                    \nEP J233704.9-101126 | 354.2696 | -10.1893 | 1.2(+/-0.3) x 10^-13 | 8.5 |          2.40          | \nEP J233641.6-101036 | 354.1735 | -10.1767 | 7.5(+/-2.2) x 10^-14 | 5.1 |          3.34          | \nEP J233642.1-101318 | 354.1754 | -10.2217 | 5.9(+/-2.0) x 10^-14 | 3.8 |          4.08          | \nEP J233708.1-101515 | 354.2836 | -10.2542 | 3.0(+/-1.3) x 10^-14 | 4.3 |          5.46          | \nEP J233710.3-100324 | 354.2929 | -10.0566 | 8.4(+/-3.0) x 10^-14 | 3.9 |          8.28          | \nEP J233727.8-100744 | 354.3657 | -10.1290 | 4.0(+/-1.6) x 10^-14 | 4.6 |          8.58          | \nEP J233636.5-100302 | 354.1522 | -10.0507 | 7.8(+/-2.2) x 10^-14 | 6.3 |          9.02          | \n-------------------------------------------------------------------------------------------------\n\nThe above observation was made with the EP-FXT instrument. 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.",
  "eventId": "GRB 240821A",
  "submittedHow": "web",
  "createdOn": 1724335149041,
  "format": "text/plain",
  "bibcode": "2024GCN.37230....1T",
  "subject": "GRB 240821A: EP-FXT follow-up observation and afterglow candidates",
  "submitter": "EP Team at NAOC/CAS <ep_ta@bao.ac.cn>",
  "circularId": 37230
}