{
  "eventId": "GRB 241112B",
  "circularId": 38182,
  "body": "J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore\n(U. Leicester), B. Sbarufatti (INAF-OAB), C. Salvaggio (INAF-OAB), M.\nFerro (INAF-OAB), M. A. Williams (PSU), S. Dichiara (PSU), J.A. Kennea\n(PSU) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT\nteam:\n\nSwift-XRT has performed follow-up observations of the\nSVOM/ECLAIRs-detected burst GRB 241112B, collecting 2.5 ks of Photon\nCounting (PC) mode data between T0+11.0 ks and T0+17.6 ks. \n\nTwo uncatalogued X-ray sources are detected consistent with being\nwithin 414 arcsec of the SVOM/ECLAIRs position, of which one (\"Source\n1\") is above the LSXPS 3-sigma upper limit at this position, and is\ntherefore likely the GRB afterglow.  The position of this source is RA,\nDec=29.0386, +9.1080 which is equivalent to:\n\nRA (J2000): 01:56:9.26\nDec(J2000): +09:06:29.0\n\nwith an uncertainty of 4.1 arcsec (radius, 90% confidence).  This\nposition is 2.5 arcmin from the SVOM/ECLAIRs position.\tThe source has\na mean count rate of 2.1e-02 ct/sec; we cannot determine at the present\ntime whether it is fading.\n\nA spectrum formed from the PC mode data can be fitted with an absorbed\npower-law with a photon spectral index of 1.9 (+0.9, -0.5). The\nbest-fitting absorption column is  9 (+30, -3) x 10^20 cm^-2,\nconsistent with the Galactic value of 5.6 x 10^20 cm^-2 (Willingale et\nal. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux\nconversion factor deduced from this spectrum  is 3.6 x 10^-11 (4.3 x\n10^-11) erg cm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     9 (+30, -3) x 10^20 cm^-2\nGalactic foreground: 5.6 x 10^20 cm^-2\nExcess significance: <1.6 sigma\nPhoton index:\t     1.9 (+0.9, -0.5)\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00021730.\nThe results of the full analysis of the XRT observations are available\nat https://www.swift.ac.uk/ToO_GRBs/00021730.\n\nThis circular is an official product of the Swift-XRT team.\n\n",
  "submitter": "Phil Evans at U of Leicester <pae9@star.le.ac.uk>",
  "submittedHow": "email",
  "bibcode": "2024GCN.38182....1O",
  "createdOn": 1731438904305,
  "subject": "GRB 241112B: Swift-XRT afterglow detection"
}