GCN Circular 8070
Subject
GRB 080804: Swift-XRT Refined Analysis
Date
2008-08-05T20:24:05Z (16 years ago)
From
Judith Racusin at PSU <racusin@astro.psu.edu>
J. Racusin, C. Pagani (PSU) report on behalf of the Swift-XRT team:
We have analysed the first five orbits of Swift-XRT data available for GRB
080804 (Racusin et al., GCN 8057) consisting of 123 s of WT mode data, and
11.0 ks of PC mode data. The enhanced XRT position is given in Beardmore
et al. (GCN Circ. 8066).
The preliminary 0.3-10.0 keV lightcurve can be fit with a single power-law
with a decay index of 1.09+/-0.03.
The WT and PC spectra can be jointly fit with an absorbed power-law with a
photon index of 1.6 +/- 0.2. The intrinsic absorption is at a level of
1.7e21 cm^-2 (using z=2.2045, Thoene et al., GCN Circ. 8058), in addition
to the Galactic absorption along the line of sight (1.6e20 cm^-2, Kalberla
et al. 2005). The average observed (unabsorbed) flux is 2.5e-10 (2.6e-10)
ergs cm^-2 s^-1 and 1.2e-11 (1.2e-11) ergs cm^-2 s^-1, for the WT and PC
spectra respectively.
Assuming the X-ray emission continues to decline at the same rate, we
predict a 0.3-10.0 keV XRT count rate of 0.008 counts/s at T+24hr, which
corresponds to an observed flux of 3.4e-13 ergs cm^-2 s^-1.
This Circular is an official product of the Swift-XRT team.