{
  "bibcode": "2008GCN..7346....1M",
  "body": "GRB080229: Swift XRT refined analysis\n\nJ.Mao, (INAF-OAB), A. Moretti (INAF-OAB), J. Canizzo (NASA/UMBC), C. \nGuidorzi\n(Univ. Bicocca & INAF-OAB), A, Beardmore (U Leicester)\nP. Evans (U Leicester) report on behalf of the Swift-XRT team:\n\nWe have analysed the first 2 orbits of Swift-XRT data obtained for\nBAT GRB 080229 (trigger #304379, Cannizzo, et al., GCN Circ. 7335).\n\nThe data consist of 149 s in Windowed Timing (WT) mode, starting 90 s\nafter the BAT trigger and 8.34 ks in Photon Counting (PC) mode.\nThe astrometrically corrected X-ray position is given  in Beardomre et \nal. GCN 7324.\n\nThe XRT light-curve shows a flare peaking few seconds after the beginning\nof the observation (103+/-2 s). The descending part of the flare can be \nfit by a power law with\na slope of alpha1=4.45+/-0.09 up to a break at t1=192.4+/- 2.5 s, which is\nfollowed by a flat decay with a slope of alpha2=0.18+/-0.01.\nA second break is present at 2700+/-1000 s with alpha3=0.8+/-0.5\n\nThe spectrum formed from all the WT data can be modeled with a\npower-law of photon index Gamma = 2.88 � 0.09, with an absorbing\ncolumn of NH = (3.1 � 0.2)e21 cm^-2 (in excess with respect to the\nGalactic value of 8.97e20 cm^-2). The spectrum formed from the PC data\ncan be modeled with a power-law of photon index Gamma = 1.99 �\n0.07, with an absorbing column of NH = (3.1 � 0.2)e21 cm^-2, which\nis in agreement with the WT one.\n\nIf the light-curve continues to decay with a slope of 0.8, the\nafterglow at 24 hour will be still bright with an expected count\nrate of 0.3 count s^-1. This corresponds to an observed (unabsorbed) flux\nof 1.41E-11(2.2e-11) erg cm-2 s-1.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 7346,
  "createdOn": 1204375174000,
  "email": "jirong.mao@brera.inaf.it",
  "subject": "GRB080229: Swift XRT refined analysis",
  "submitter": "Jirong Mao at INAF-OAB  <jirong.mao@brera.inaf.it>",
  "eventId": "GRB 080229"
}