{
  "body": "P.A. Evans (U. Leicester), J.A. Kennea (PSU), E. Ambrosi  (INAF-IASFPA) , A.P.\nBeardmore (U. Leicester), M.G. Bernardini (INAF-OAB), R. Brivio (INAF-OAB), D.N.\nBurrows (PSU), S. Campana (INAF-OAB), M. Capalbi (INAF-OAR), A. D'Ai (INAF-IASFPA),\nP. D'Avanzo (INAF-OAB), V. D'Elia (SSDC & INAF-OAR), S. Dichiara (PSU), M. Ferro\n(INAF-OAB), A. Melandri (INAF-OAR), J.P. Osborne (U. Leicester), K.L. Page (U.\nLeicester), M. Perri (SSDC & INAF-OAR), C. Salvaggio (INAF-OAB), T. Sbarrato\n(INAF-OAB), B. Sbarufatti (INAF-OAB), M.A. Williams (PSU) report on behalf of the\nSwift-XRT team:\n\nSwift-XRT has performed follow-up observations of the SVOM/ECLAIRs-detected source\nGRB 250713A, collecting 2.0 ks of Photon Counting (PC) mode data between T0+429 s\nand T0+6.4 ks after the trigger. We have detected 1 source. This has been\nautomatically classified as an uncatalogued X-ray source.\n\nUncatalogued X-ray sources\n--------------------------\n\n  Source 1 (SWIFT J222820.3+385214):\n  ==================================\n    RA (J2000.0):  337.0847  =\t22h 28m 20.33s\n    Dec (J2000.0): +38.8706  =\t+38d 52' 14.2\"\n    Error:\t   7.0 (arcsec, radius, 90% confidence).\n    Detect flag:   GOOD\n    Distance:\t   8.2 arcmin from the SVOM/ECLAIRs position.\n    Mean rate:\t   (7.7 [+2.8, -2.3])e-3 ct s^-1\n    Mean flux:\t   (2.94 [+1.07, -0.88])e-13 erg cm^-2 s^-1\n    Peak rate:\t   (7.7 [+2.8, -2.3])e-3 ct s^-1\n    Peak flux:\t   (2.94 [+1.07, -0.88])e-13 erg cm^-2 s^-1\n    ECF:\t   3.84e-11 erg cm^-2 ct^-1, assuming NH=1.27e+21 cm^-2,\n\t\t   gamma=1.63; determined from a spectral fit.\n    XMM UL:\t   2.2e-12 erg cm^-2 s^-1, (0.3-10 keV)\n\t so the source is 19.2-sigma above this 3-sigma upper limit.\n    There is no evidence for fading.\n\nThis source is not spatially consistent with any of those detected by EP-FXT (Circ.\n41085).\n\nAll fluxes are 0.3-10 keV, observed. For all flux conversions and comparisons with\ncatalogues and upper limits  from other missions, we assumed a power-law spectrum\nwith NH=3x10^20 cm^-2 and photon index (Gamma)=1.7 unless otherwise stated.\n\nThe results of the XRT-team automatic analysis of the XRT observations, including a\nposition-specific upper limit calculator, are available at\nhttps://www.swift.ac.uk/SVOM.\n\nThis circular is an officicial product of the Swift-XRT team.\n\n\n",
  "bibcode": "2025GCN.41086....1E",
  "subject": "GRB 250713A: Swift-XRT observations",
  "submittedHow": "email",
  "submitter": "Phil Evans at U of Leicester <pae9@star.le.ac.uk>",
  "circularId": 41086,
  "eventId": "GRB 250713A",
  "createdOn": 1752472715272
}