TITLE:   GCN CIRCULAR
NUMBER:  8193
SUBJECT: GRB 080905B: Swift-XRT Refined Analysis
DATE:    08/09/07 07:06:17 GMT
FROM:    Michael Stroh at PSU/Swift  <stroh@astroh.org>

M.C. Stroh (PSU) reports on behalf of the Swift-XRT team:

We have analyzed the Swift-XRT data obtained for GRB 080905B (Stroh et  
al., GCN Circ. 8182), totaling 85s of Windowed Timing and 10.2ks of  
Photon Counting data.

The 0.3-10 keV X-ray light-curve can be fit by a double broken power- 
law with an initial decay index of 2.46 +/- 0.18, second decay index  
of 0.01 +/- 0.18, and a third decay index of 1.41 +/- 0.4 with first  
and second break points at 258s and 2734s respectively. We predict  
counting rates of 7.88e-3 cts/s and 4.44e-3 cts/s at T+48 and T+72  
hours.

The spectrum from the Windowed Timing data can be fit with a power-law  
in excess of the Galactic value (3.5e20 cm-2, Kalberla et al. 2005),  
with an intrinsic column density of 1.32 (+0.57/-0.48)e22 cm^-2 and a  
photon index of 1.49 (+0.13/-0.12). The observed (unabsorbed) 0.3-10  
keV flux is 5.34e-10 (6.1e-10) ergs/cm^2/s.

The spectrum from the Photon Counting data can be fit with a power law  
with intrinsic column density of 2.26 (+0.53/-0.47)e22 cm^-2 and a  
photon index of 1.92 (+0.10/-0.10). The observed (unabsorbed) 0.3-10  
keV flux is 1.259e-10 (1.7e-10) ergs/cm^2/s.

This is an official product of the Swift-XRT team.