{
  "createdOn": 1721122573077,
  "bibcode": "2024GCN.36882....1E",
  "body": "P. A. Evans (U. Leicester), K.L. Page (U. Leicester), C. Salvaggio\n(INAF-OAB), T. Sbarrato (INAF-OAB) and B. Sbarufatti (INAF-OAB) reports\non behalf of the Swift-XRT team:\n\nWe have analysed 1.7 ks of XRT data for the Swift/BAT-detected burst\nGRB 240712A, from 152 s to 5.3 ks after the  Swift/BAT trigger. The\ndata are entirely in Photon Counting (PC) mode. Using 1421 s of PC mode\ndata and 2 UVOT images, we find an enhanced XRT position (using the\nXRT-UVOT alignment and matching UVOT field sources to the USNO-B1\ncatalogue): RA, Dec = 122.33591, -37.08814 which is equivalent to:\n\nRA (J2000): 08h 09m 20.62s\nDec(J2000): -37d 05' 17.3\"\n\nwith an uncertainty of 3.2 arcsec (radius, 90% confidence). This\nposition is 103 arcsec from the Swift/BAT position. \n\nThe light curve can be modelled with a power-law decay with a decay\nindex of alpha=0.9 (+/-0.4).\n\nA spectrum formed from the PC mode data can be fitted with an absorbed\npower-law with a photon spectral index of 1.5 (+1.1, -1.0). The\nbest-fitting absorption column is  2.6 (+2.5, -1.7) x 10^22 cm^-2,\nconsistent with the Galactic value of 8.9 x 10^21 cm^-2 (Willingale et\nal. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux\nconversion factor deduced from this spectrum  is 9.0 x 10^-11 (1.4 x\n10^-10) erg cm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     2.6 (+2.5, -1.7) x 10^22 cm^-2\nGalactic foreground: 8.9 x 10^21 cm^-2\nExcess significance: <1.6 sigma\nPhoton index:\t     1.5 (+1.1, -1.0)\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/01242223.\n\nThis circular is an official product of the Swift-XRT team.\n\n",
  "eventId": "GRB 240712A",
  "submittedHow": "email",
  "subject": "GRB 240712A: Swift-XRT refined Analysis",
  "circularId": 36882,
  "submitter": "Phil Evans at U of Leicester <pae9@star.le.ac.uk>"
}