[vsnet-grb-info 2896] GRB060210: Swift XRT Refined Analysis

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4733
SUBJECT: GRB060210: Swift XRT Refined Analysis
DATE:    06/02/10 13:36:53 GMT
FROM:    Andy Beardmore at U Leicester  <apb at 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.