{
  "bibcode": "2014GCN.15798....1M",
  "body": "A. Maselli (INAF-IASFPA), A. Y. Lien (NASA/GSFC/ORAU) and P. A. Evans\n(U. Leicester) report on behalf of the Swift-XRT team:\n\nWe have analysed 14 ks of XRT data for GRB 140206A (Lien et al. GCN\nCirc. 15784), from 33 s to 30.2 ks after the BAT trigger. The data\ncomprise 1.2 ks in Windowed Timing (WT) mode (the first 9 s were taken\nwhile Swift was slewing) with the remainder in Photon Counting (PC)\nmode. The enhanced XRT position for this burst was given by Osborne et\nal. (GCN Circ. 15793).\n\nThe light curve shows initial flaring activity with two flares peaking\nat about 61 s and 223 s after the trigger. The underlying emission can\nbe modelled with a broken power-law decay: a flat decay with an index\nalpha=0.756 (+0.026, -0.028), a break at T+10.7 ks and a late-time\ndecay with an index 1.31 (+0.15, -0.12).\n\nA spectrum formed from the WT mode data can be fitted with an absorbed\npower-law with a photon spectral index of 1.762 (+/-0.028). The\nbest-fitting absorption column is 1.25 (+/-0.07) x 10^21 cm^-2, in\nexcess of the Galactic value of 4.8 x 10^20 cm^-2 (Kalberla et al.\n2005). The PC mode spectrum has a photon index of 1.95 (+0.08, -0.07)\nand a best-fitting absorption column of 1.22 (+0.19, -0.18) x 10^21\ncm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion\nfactor deduced from this spectrum  is 3.8 x 10^-11 (4.9 x 10^-11) erg\ncm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     1.22 (+0.19, -0.18) x 10^21 cm^-2\nGalactic foreground: 4.8 x 10^20 cm^-2\nExcess significance: 6.6 sigma\nPhoton index:\t     1.95 (+0.08, -0.07)\n\nIf the light curve continues to decay with a power-law decay index of\n1.31, the count rate at T+24 hours will be 0.088 count s^-1,\ncorresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.3 x\n10^-12 (4.3 x 10^-12) erg cm^-2 s^-1.\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00585834.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 15798,
  "createdOn": 1391720255000,
  "email": "maselli@ifc.inaf.it",
  "subject": "GRB 140206A: Swift-XRT refined Analysis",
  "submitter": "Alessandro Maselli at INAF/IASF Palermo  <maselli@ifc.inaf.it>",
  "eventId": "GRB 140206A"
}