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GCN Circular 15173

GRB 130903A: Swift-XRT observations
2013-09-03T20:11:17Z (11 years ago)
Dirk Grupe at PSU/Swift-XRT <>
Dirk Grupe (PSU) and Stephen Holland (STSCI) report on behalf of the
Swift team:

We have analysed 3.2 ks of XRT data for the INTEGRAL-detected burst:
GRB 130903A,  from 39.6 ks to 46.4 ks after the  INTEGRAL trigger. The
data are entirely in Photon Counting (PC) mode.  An X-ray source is
detected within the INTEGRAL error circle (Mereghetti et al., GCN circ.
15169). Using 1789 s of PC mode data and 1 UVOT images, we find an
enhanced XRT position (using the XRT-UVOT alignment and matching UVOT
field sources to the USNO-B1 catalogue): RA, Dec = 82.13013, -0.12667
which is equivalent to:

RA (J2000): 05h 28m 31.23s
Dec(J2000): -00d 07' 36.0"

with an uncertainty of 4.3 arcsec (radius, 90% confidence). This
position is 12 arcsec from the INTEGRAL position.  Currently the source
has a 0.3-10 keV count rate in the Swift XRT of (4.9+4.9-3.0)e-3
We cannot determine at the present time whether the source is fading.

The results of the XRT-team automatic analysis are available at

The Swift UVOT observed the field of GRB 130903A in V and U for 2462
and 780s, respectively. No optical counterpart was found. The 3-sigma
upper limits at the position of the X-ray source are 20.6 in V and 20.4
in U.

This circular is an official product of the Swift team.
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