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GCN Circular 23296

GRB 181003A: Swift-XRT observations
2018-10-03T06:56:48Z (6 years ago)
Phil Evans at U of Leicester <>
P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), D.N. Burrows
(PSU), J.A. Kennea (PSU), M. Perri (ASDC) and G. Tagliaferri (INAF-OAB)
report on behalf of the Swift-XRT team:

The XRT began observing the field of GRB 181003A at 06:02:32.6 UT,
3089.4 seconds after the BAT trigger. Using promptly downlinked data we
find an uncatalogued X-ray source located at RA, Dec 52.52910,
-33.96445 which is equivalent to:
   RA(J2000)  = 03h 30m 06.98s
   Dec(J2000) = -33d 57' 52.0"
with an uncertainty of 4.5 arcseconds (radius, 90% containment). This
location is 242 arcseconds from the BAT onboard position. This position
may be improved as more data are received; the latest position is
available at  We cannot determine whether
the source is fading at the present time. As this position is
significantly outside the BAT error circle, it is probably unrelated to
the trigger. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 1.24
x 10^20 cm^-2 (Willingale et al. 2013).
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