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GCN Circular 21828

GRB 170906C: Swift-XRT observations
2017-09-06T08:30:41Z (7 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), S. Campana (INAF-OAB) and G. Cusumano
(INAF-IASF PA) report on behalf of the Swift-XRT team:

The XRT began observing the field of GRB 170906C at 07:47:49.6 UT,
1292.1 seconds after the BAT trigger. Using promptly downlinked data we
find an uncatalogued X-ray source located at RA, Dec 128.65022,
70.81211 which is equivalent to:
   RA(J2000)  = 08h 34m 36.05s
   Dec(J2000) = +70d 48' 43.6"
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This
location is 125 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (3.30 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 1.1
(+0.39/-0.34) x 10^22 cm^-2 (90% confidence).
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