GCN Circular 3873
Subject
GRB 050822: refined XRT analysis
Date
2005-08-25T09:48:17Z (19 years ago)
From
Kim Page at U.of Leicester,Swift SDC <kpa@star.le.ac.uk>
O. Godet, K.L. Page, J.P. Osborne (U. Leicester), D. N. Burrows (PSU),
N. Gehrels (NASA/GSFC), K. Hurley (Berkeley), M. Chester (PSU) report on
behalf of the Swift XRT team:
We have analysed the Swift XRT data taken up to 200 ksec (2.3 days) from
the burst GRB 050822. The refined coordinates are:
RA(J2000) = 03h 24m 26.70s
Dec(J2000) = -46d 02' 01.7"
with an uncertainty of 6 arcseconds radius (90% containment).
This position is consistent with that reported by Blustin et al. (GCN
3849).
Initial data show a rapid decay until ~1000 sec, followed by a shallow
decay (power law decline index ~0.4) until ~20 ksec. After this the flux
declines more steeply, with an index ~1.2.
The X-ray spectrum before and after the ~20 ksec break is well fit
by a power-law with Gamma = 2.17+/-0.28 (90% confidence) and an
absorbing column of ~1.4e21 cm^-2 in excess of Galactic in the observer
frame.
At 200 ksec after the burst the XRT count rate was 0.007 c/s,
corresponding to an unabsorbed 0.3-10 keV flux of 3x10^-13 erg/cm2/s.