{
  "bibcode": "2008GCN..8244....1S",
  "body": "R.L.C. Starling (U. Leicester) and H. Ziaeepour (MSSL-UCL) report on \nbehalf of the Swift-XRT team:\n\nWe have analysed the first two orbits of Swift XRT data for GRB 080916A \n(Ziaeepour et al., GCN Circ. 8237) from T0+70 s to T0+7440 s with total \nexposure time 3.4 ks. The enhanced X-ray position is given in Evans et \nal., GCN Circ. 8241. \n\nThe light curve can be represented by a 5-segment broken power law with an \ninitial decay alpha1=1.3+0.4/-0.6 breaking at Tbk1=102+4/-6 s to a steep \ndecay of alpha2=3.5+/-0.3 until Tbk2=190+25/-13 s. The light curve then \nflattens to alpha3=1.07+0.06/-0.3 and breaks at Tbk3=690+150/-140 s to a \nfurther steep decay of alpha4=2.9+2/-0.8. From Tbk4=1270+240/-220 s the \ndecay becomes shallow again with alpha5=0.3+/-0.2. \n\nThe spectrum from 3.2 ks of Photon Counting mode data can be fit with an \nabsorbed power law with photon index Gamma=2.1+/-0.2 and intrinsic \nabsorption (in excess of the Galactic value of 1.8e20 cm-2) of \nnH=(2.6+0.7/-0.6)e21 cm-2. This is consistent with the spectrum formed \nfrom the initial 170 s of Windowed Timing mode data. The observed \n(unabsorbed) count rate to flux conversion is 1 count/s = 4.0e-11 \n(6.8e-11) erg/cm2/s. \n\nThe predicted count rate at T+24hr would be approximately 0.1 count/s if \nthe decay continues on the current plateau-like phase.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 8244,
  "createdOn": 1221585597000,
  "email": "rlcs1@star.le.ac.uk",
  "subject": "GRB 080916A: Swift XRT refined analysis",
  "submitter": "Rhaana Starling at U of Leicester  <rlcs1@star.le.ac.uk>",
  "eventId": "GRB 080916A"
}