GCN Circular 5703
Subject
GRB 061006: Swift-XRT Team Refined Analysis
Date
2006-10-07T02:24:20Z (18 years ago)
From
Eleonora Troja at INAF-IASFPA <nora@ifc.inaf.it>
E. Troja (U. Leicester/INAF-IASFPa), K. L. Page(U. Leicester),
D. N. Burrows (PSU) & P. Schady (MSSL-UCL) report on behalf of the Swift-XRT
Team:
We have analysed the first 4 orbits of Swift-XRT data obtained for GRB 061006
(GCN Circ. 5699; Schady et al.). Our data set consists of 7.8 ks in Photon
Counting (PC) mode.
We derived a XRT refined position of:
RA(J2000) = 07h 24m 06.36s
Dec(J2000) = -79d 11' 56.80''
with an estimated error radius of 6 arcsec (90% containment, including
boresight uncertainties). This lies 2.3 arcsec from the preliminary XRT
position and 45'' arcsec from the on-board calculated BAT position, reported
in GCN 5699.
The X-ray lightcurve shows an initial slope of 2.26 +/- 0.10, breaking around
290 s after the burst to a flatter decay slope of 0.77 +/- 0.07.
The time-averaged spectrum (from T+155 s to T+18.6 ks) can be fit with an
absorbed power-law with a photon index of 1.7 +/- 0.4 and an absorption
column of 1.8e21 cm^-2, consistent at the 90% confidence level with the
Galactic value in the direction of the burst (1.33e21 cm^-2).
The mean observed (unabsorbed) flux in the 0.2-10 keV energy band is 1.4e-12
(1.9e-12) erg cm^-2 s^-1.
If the afterglow continues decaying at the same rate, the count rate at T+24 h
is predicted to be 1.8e-3 cts s^-1, corresponding to an unabsorbed 0.2-10 keV
flux of 1.5e-13 erg cm^-2 s^-1.
This circular is an official product of the Swift-XRT team.