{
  "bibcode": "2008GCN..8705....1G",
  "body": "Dirk Grupe (PSU) reports on behalf of the Swift-XRT team:\n\n\nThe XRT began observing the field of GRB 081222 (trigger=337914; Grupe et al.,\nGCN Circ 8691) on 2008-December-22 at 04:54:51.7 UT, 51.8 seconds after\nthe BAT trigger.\n\n\nThe 0.3-10 keV X-ray light curve of the first five orbits\ndisplays a smooth light curve that can be fitted with an initial decay slope\nalpha1 = 0.90+/-0.02 with a break at 1420+/-100s followed by a steeper decay\nslope alpha2=1.20+/-0.02.\n\nThe spectrum of the Windowed Timing data of the first orbit\ncan be well fitted by an absorbed single\npower law model with a photon\nindex Gamma = 2.01 +/- 0.20 and a column density\nNH=(4.61+/-0.80)e20 which is in excess of the Galactic column density in the\ndirection of the burst of NH-gal=2.24e20 (Kalberla et al. 2005).\nThe photon counting mode data of the first five orbits are consistent \nwith this\nresult.\n\n\nIf the underlying power law decay of 1.2\ncontinues as is, we predict an XRT count rate\nof 0.030 counts/s at T+24 hours or 1e-12 ergs/s/cm2 and at T+48 hours 0.015\ncounts/s or 5e-13 ergs/s/cm2.\n\nThis circular is an official product of the Swift-XRT team.\n\n[GCN OPS NOTE(23dec08):  Per author's request, the \"081221\" in the first line\nwas changed to \"081222\".]",
  "circularId": 8705,
  "createdOn": 1229962452000,
  "email": "grupe@astro.psu.edu",
  "subject": "GRB 081222: Swift XRT refined analysis",
  "submitter": "Dirk Grupe at PSU/Swift-XRT  <grupe@astro.psu.edu>",
  "eventId": "GRB 081222"
}