TITLE:   GCN CIRCULAR
NUMBER:  16146
SUBJECT: GRB 140423A: Swift-XRT observations
DATE:    14/04/23 10:13:31 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

D.N. Burrows (PSU), J.A. Kennea (PSU), S. Campana (INAF-OAB), G.
Cusumano (INAF-IASF PA), P.A. Evans (U. Leicester) and J.P. Osborne (U.
Leicester) report on behalf of the Swift-XRT team:

The XRT began observing the field of GRB 140423A at 09:20:56.7 UT,
2943.5 seconds after the BAT trigger. Using promptly downlinked data we
find an uncatalogued X-ray source located at RA, Dec 197.28927,
49.84233 which is equivalent to:
   RA(J2000)  = 13h 09m 09.42s
   Dec(J2000) = +49d 50' 32.4"
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This
location is 98 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 http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.09 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 3.4
(+2.57/-1.42) x 10^21 cm^-2 (90% confidence).