{
  "circularId": 41765,
  "submitter": "Phil Evans at U of Leicester <pae9@star.le.ac.uk>",
  "createdOn": 1757433943414,
  "subject": "EP#01709240653: Swift-XRT observations",
  "submittedHow": "email",
  "bibcode": "2025GCN.41765....1E",
  "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 Einstein Probe/WXT-detected\nsource EP#01709240653, collecting 1.8 ks of Photon Counting (PC) mode data between\nT0+859 s and T0+6.8 ks after the trigger. We have detected 2 sources.  These have\nbeen automatically classified as follows:\n  * 0 likely counterparts\n  * 0 candidate counterparts\n  * 2 uncatalogued X-ray sources\n  * 0 known X-ray sources\n\nUncatalogued X-ray sources\n--------------------------\n\n  Source 1 (SWIFT J194954.4-572931):\n  ==================================\n    RA (J2000.0):   297.4769  =  19 49 54.46\n    Dec (J2000.0):  -57.4921  =  -57 29 31.6\n    Error:\t    5.7 (arcsec, radius, 90% confidence).\n    Detect flag:    GOOD\n    Distance:\t    1.6 arcmin from the Einstein Probe/WXT position.\n    Mean rate:\t    0.0334 [+0.0053, -0.0052] ct s^-1\n    Mean flux:\t    (8.9 +/- 1.4)e-13 erg cm^-2 s^-1\n    Peak rate:\t    0.085 +/- 0.025 ct s^-1\n    Peak flux:\t    (2.25 +/- 0.66)e-12 erg cm^-2 s^-1\n    ECF:\t    2.65e-11 erg cm^-2 ct^-1\n\t\t      assuming NH=4.43e+20 cm^-2, gamma=2.38\n\t\t      determined from a spectral fit.\n    XMM UL:\t    2.1e-12 erg cm^-2 s^-1, (0.3-10 keV)\n\t\t      so the source is 0.3-sigma above this 3-sigma upper limit.\n    The source may be fading, at the 1.9-sigma level.\n    There are 2 2MASS objects within the source's 3-sigma error radius.\n\n  Source 5 (SWIFT J194951.3-573147):\n  ==================================\n    RA (J2000.0):   297.4638  =  19 49 51.31\n    Dec (J2000.0):  -57.5299  =  -57 31 47.6\n    Error:\t    6.8 (arcsec, radius, 90% confidence).\n    Detect flag:    POOR\n    Distance:\t    1.8 arcmin from the Einstein Probe/WXT position.\n    Mean rate:\t    (-1.0 +/- -1.0)e0 ct s^-1\n    Mean flux:\t    (-4.3 +/- -4.3)e-11 erg cm^-2 s^-1\n    Peak rate:\t    (6.0 [+4.5, -3.2])e-3 ct s^-1\n    Peak flux:\t    (2.6 [+1.9, -1.4])e-13 erg cm^-2 s^-1\n    XMM UL:\t    1.9e-12 erg cm^-2 s^-1, (0.3-10 keV)\n\t\t      so the source is not above this 3-sigma upper limit.\n    There is no evidence for fading.\n    There is 1 2MASS object within the source's 3-sigma error radius.\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/EP/EP_FIELD00071.\n\nThis circular is an official product of the Swift-XRT team.\n\n\n"
}