{
  "bibcode": "2012GCN.13453....1P",
  "body": "K.L. Page (U. Leicester) and M. J. Page (UCL-MSSL) report on behalf of\nthe Swift-XRT team:\n\nWe have analysed 4.5 ks of XRT data for GRB 120711B (Page  et al. GCN\nCirc. 13431), from 208 s to 47.2 ks after the  BAT trigger. The data\ncomprise 106 s in Windowed Timing (WT) mode with the remainder in\nPhoton Counting (PC) mode. Using 551 s of PC mode data and 2 UVOT\nimages, we find an enhanced XRT position (using the XRT-UVOT alignment\nand matching UVOT field sources to the USNO-B1 catalogue): RA, Dec =\n331.69137, +60.02267 which is equivalent to:\n\nRA (J2000): 22h 06m 45.93s\nDec(J2000): +60d 01' 21.6\"\n\nwith an uncertainty of 1.8 arcsec (radius, 90% confidence).\n\nThe light curve can be modelled with  a power-law decay with a decay\nindex of alpha=1.69 (+0.22, -0.17).\n\nA spectrum formed from the WT mode data can be fitted with an absorbed\npower-law with a photon spectral index\tof 1.8 (+0.5, -0.4). The\nbest-fitting absorption column is  2.4 (+0.9, -0.8) x 10^22 cm^-2, in\nexcess of the Galactic value of 7.2 x 10^21 cm^-2 (Kalberla et al.\n2005). The PC mode spectrum has a photon index of 1.5 (+0.4, -0.3) and\na best-fitting absorption column of 2.9 (+0.7, -0.6) x 10^22 cm^-2. The\ncounts to observed (unabsorbed) 0.3-10 keV flux conversion factor\ndeduced from this spectrum  is 9.9 x 10^-11 (1.7 x 10^-10) erg cm^-2\ncount^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     2.9 (+0.7, -0.6) x 10^22 cm^-2\nGalactic foreground: 7.2 x 10^21 cm^-2\nExcess significance: 5.6 sigma\nPhoton index:\t     1.5 (+0.4, -0.3)\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00526270.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 13453,
  "createdOn": 1342072694000,
  "email": "klp5@leicester.ac.uk",
  "subject": "GRB 120711B: Swift-XRT refined Analysis",
  "submitter": "Kim Page at U.of Leicester  <klp5@leicester.ac.uk>",
  "eventId": "GRB 120711B"
}