GCN Circular 4232
Subject
GRB051109B: XRT refined analysis
Date
2005-11-09T18:42:43Z (19 years ago)
From
Gianpiero Tagliaferri at OAB-INAF <taglia@merate.mi.astro.it>
G. Tagliaferri (INAF-OAB), S. Campana (INAF-OAB),
P. Romano (INAF-OAB), T. Mineo (INAF-IASFPA),
D.N. Burrows (PSU) report on behalf of the Swift/XRT team:
We have analysed 4.3 ks of XRT observations of the afterglow of
GRB051109B (Tagliaferri et al., GCN 4222; Campana et al. GCN4226).
The X-ray light-curve from 100s after the burst up to about 10 ks
after the burst is quite flat and well represented by a single power
law with a decay index alpha=-0.55+/-0.08 (90% containment).
The spectrum can be modeled with a power-law with photon index
Gamma = 2.33+/-0.30 (90% containment). There is evidence for an
absorbing column higher than the Galactic value (1.3e21 cm^-2)
at a level of (3.1+/-1.2)e21 cm^-2.
At 200 s the 0.5-10 keV unabsorbed flux was 1.7e-10 erg cm^-2 s^-1.
At 10000 s the afterglow had faded to flux level of 2.0e-12 erg cm^-2 s^-1.
Assuming the current flat decay we predict a flux of ~5.6e-13 erg cm^-2 s^-1
at 1 d from the burst.
[GCN_OPS_NOTE(10nov05): Per author's request, the flux level in the
last paragraph "2.0e-11" was changed to "2.0e-12".]