[vsnet-grb-info 8470] GRB 091003: Swift XRT analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9986
SUBJECT: GRB 091003: Swift XRT analysis 
DATE:    09/10/04 00:44:01 GMT
FROM:    Rhaana Starling at U of Leicester  <rlcs1 at star.le.ac.uk>

R.L.C. Starling and A.P. Beardmore (U. Leicester) report on behalf
of the Swift-XRT team:

The Swift X-ray Telescope (XRT) observed the Fermi GBM/LAT and
Integral-detected GRB 091003 (Rau GCN Circ. 9983; McEnery et al. GCN
Circ. 9985) on 2009 October 3 at 20:07:28 UT, 15.5 hours after the
Fermi trigger.

In 2.5 ks of photon counting mode data we detect an uncatalogued
X-ray source at  RA, Dec = 251.52047, 36.62548 degrees, which is
equivalent to:

RA (J2000) = 16:46:04.9
Dec (J2000) = +36:37:31.74

with an uncertainty of 3.7 arcsec (radius, 90% containment). This
is 6.85 arcmin from the Fermi LAT position and within its error circle.

A spectrum formed from these data can be fit with an absorbed power law of
photon index 1.7+/-0.3, with nH < 2e21 cm-2, and has an observed 0.3-10 keV 
count rate of 0.087+/-0.007 count/s corresponding to a flux of 3.6e-12 
erg/cm2/s.

At this stage we do not have enough data to tell if the source is fading.

This circular is an official product of the Swift-XRT team.