GCN Circular 4733
Subject
GRB060210: Swift XRT Refined Analysis
Date
2006-02-10T13:36:53Z (19 years ago)
From
Andy Beardmore at U Leicester <apb@star.le.ac.uk>
A.P. Beardmore, S. Mateos, K.L. Page (UL), D.N. Burrows (PSU) report on
behalf of the Swift XRT Team.
We have analysed the Swift XRT data from the first 3 orbits of GRB
060210 (Beardmore et al, GCN 4724). The refined XRT position from 2.5 ks
of photon counting mode data is
RA(J2000) = 3h 50m 57.4s
Dec(J2000) = +27d 01' 36.4"
with an estimated uncertainty of 3.6 arcsec (90% containment).
This position is 29.5 arcseconds from the BAT position given in GCN 4724
and 2.0 arcseconds from the optical afterglow position reported in GCN
4726 (Mundell et al).
The fading X-ray light curve shows 2 strong flares 200 s and 385 s
after the BAT trigger. Fitting a power law to the data
after the flares gives a late time decay slope of 0.7.
The X-ray spectrum from the first orbit (T+103s to T+600s) is well fit
by an absorbed power law, with a photon index of 1.93+/-0.03 and a
column density of 1.64+/-0.3 e22 cm**-2 in the rest frame of the burst
(assuming z = 3.91; Cucchiara et al, GCN 4729), in addition to the
Galactic value of 8.5e20 cm**-2. The observed 0.2-10 keV flux is
9.4e-10 ergs cm**-2 s**-1, which corresponds to an unabsorbed flux of
1.3e-09 ergs cm**-2 s**-1.
Assuming the X-ray emission from the GRB continues to decay at the
same rate, the predicted count rate 24 hrs after the burst trigger is
0.1 count/s, which corresponds to an observed (unabsorbed) 0.2-10 keV
flux of 3.4e-12 (4.8e-12) ergs cm**-2 s**-1.
This circular is an official product of the Swift XRT Team.