GCN Circular 3602
Subject
GRB050713b: XRT refined analysis
Date
2005-07-13T21:37:29Z (19 years ago)
From
David Burrows at PSU/Swift <dxb15@psu.edu>
K. Page, S. Vaughan, M. Goad (Leicester), D. N. Burrows (PSU), M. Ajello
(MPE), R. Fink and N. Gehrels (GSFC) report on behalf of the Swift XRT team:
We have analysed the first two orbits of data for GRB050713b (GCN 3590,
Vaughan et al., 2005). Using xrtcentoid, the refined position is:
RA(J2000) = 20h 31m 15.5s
Dec(J2000) = +60d 56' 40.4"
with an uncertainty of 6 arcsec. This is only 2 arcsec from the original
XRT position (GCN 3590, Vaughan et al., 2005).
The light-curve shows a steeply fading afterglow during the first orbit,
with a decay slope of
alpha = 2.88 +/- 0.12 between 143 and 600 seconds after the trigger. After
~5000 seconds (i.e. on the second orbit), the light-curve flattens
significantly; more data are required to constrain the slope following the
break in the light curve.
The WT spectrum can be fitted by an absorbed power-law with a spectral
index, Gamma = 1.70 +0.11/-0.09 and excess NH of (1.97 +0.50/-0.43)e21
cm^-2.
The unabsorbed 0.3-10 keV flux (averaged over 143 and 330 seconds after
the burst) is (9.02 +0.16/0.80)e-10 erg cm^-2 s^-1.