{
  "bibcode": "2008GCN..7694....1S",
  "body": "B. Sbarufatti, V. Mangano, V. La Parola (INAF-IASF PA) and\nW. H. Baumgartner (GSFC/UMBC)\n\nThe Swift-XRT began observing GRB 080506 (trigger=311159, Baumgartner\net al., GCN Circ. 7685) in Window Timing mode, 146 s after the BAT\ntrigger. The enhanced XRT position was given in Osborne et al.\n(GCN Circ. 7687).\n\nThe lightcurve is quite complex. It shows two initial bright flares\ncentered at 182+/-2 s and 254+/-2 s, with folding times of 22+/-1 s\nand 88+/-2 s, respectively. Flaring activity is detected until times\n > T+10 ks. The decay slope after 10 ks from the trigger time is\n-0.6+/-0.2.\n\nThe spectrum of the first flare can be fit by a power-law model, with\na photon index of 1.46 � 0.06 and column density consistent with the\naverage Galactic column density in this direction of 1.66e21 cm-2\n(Kalberla et al 2005). The observed (unabsorbed) 0.3-10 keV flux is\n1.5e-9 (1.8e-9) erg cm-2 s-1.\n\nThe spectrum of the second flare can be fit by a power-law model, with\na photon index of 2.3 � 0.1 and column density consistent with the\naverage Galactic column density in this direction. The observed\n(unabsorbed) 0.3-10 keV flux is 3.2e-10 (5.2e-9) erg cm-2 s-1.\n\nThe PC mode spectrum, covering times > T+1000 s, is fit by a power\nlaw model with photon index 2.0 � 0.2 and no evidence for any\nadditional column density with respect to the Galactic one.\nThe corresponding observed (unabsorbed) 0.3-10 keV fluxes are\n2.3e-12 (3.5e-12 ) erg cm-2 s-1, respectively.\n\nIf the burst continues to decay at the same rate, we predict an XRT\ncount rate of 9.8 e-3 counts/s and 6.4 e-3 counts/s at T+24 hours\nand T+48 hours, respectively. This corresponds to observed 0.3-10\nkeV fluxes of approximately 5.4e-13 and 3.6e-13 erg cm-2 s-1.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 7694,
  "createdOn": 1210182576000,
  "email": "sbarufatti@ifc.inaf.it",
  "subject": "GRB 080506: Swift XRT refined analysis",
  "submitter": "Boris Sbarufatti at INAF-IASF-Pa  <sbarufatti@ifc.inaf.it>",
  "eventId": "GRB 080506"
}