{
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Simone Dichiara at Pennsylvania State University <sbd5667@psu.edu>",
  "circularId": 40037,
  "format": "text/plain",
  "createdOn": 1743737527873,
  "editedOn": 1743774098815,
  "eventId": "GRB 250403A",
  "submittedHow": "web",
  "subject": "GRB 250403A: Swift-XRT observations",
  "body": "S. Dichiara (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB), K.L. \nPage and P.A. Evans (U.Leicester) reports on behalf of the Swift-XRT team:\n\nWe have analysed  401 s of XRT data for the GRB 250403A detected by \nFermi GBM (Fermi team, GCN circ. 40025) and SVOM/ECLAIRs (SVOM trigger \nsb25040305; Julakanti et al., GCN circ. 40026), from T0+7.62 ks to T0+8.02 \nks after the SVOM/ECLAIRs trigger. The data are entirely in Photon Counting \n(PC) mode.\n\nWe find an uncatalogued X-ray source 3.1 sigma above the RASS limit, \nconsistent with the reported optical counterpart (Starling et al., \nGCN 40028, Chao et al., GCN 40029, Guowang et al., GCN 40031, Li et al., GCN \n40032). Details of this source are given below:\n\nSource 1:\n  RA (J2000.0):   194.6162  =  12:58:27.90\n  Dec (J2000.0): -24.3800  =  -24:22:47.9\n  Error: 3.7 arcsec (radius, 90% conf. [Enhanced position])\n  Count-rate: 0.29 (±0.07) ct s-1   \n  Flux: 1.2 (±0.3) ×10-11 erg cm-2 s-1 (observed, 0.3-10 keV)\n\nThis XRT position is 2.5 arcsec away from the optical position (Starling et \nal., GCN 40028).\nThe results of the XRT-team automatic analysis of the XRT observations, \nincluding a position-specific upper limit calculator, are available at \nhttps://www.swift.ac.uk/SVOM/SVOM_FIELD00010/.\n\nThis circular is an official product of the Swift-XRT team.",
  "submitter": "Simone Dichiara at Pennsylvania State University <sbd5667@psu.edu>",
  "bibcode": "2025GCN.40037....1D",
  "version": 2
}