[vsnet-grb-info 13733] GRB 130727A: Swift-XRT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15048
SUBJECT: GRB 130727A: Swift-XRT observations
DATE:    13/07/27 18:38:48 GMT
FROM:    Phil Evans at U of Leicester  <pae9 at leicester.ac.uk>

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

The XRT began observing the field of GRB 130727A at 17:43:24.0 UT,
3484.5 seconds after the BAT trigger. Using promptly downlinked data we
find an uncatalogued X-ray source with an enhanced position: RA, Dec
330.7988, -65.5384 which is equivalent to:
   RA(J2000)  = 22h 03m 11.70s
   Dec(J2000) = -65d 32' 18.4"
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This
location is 131 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 (2.79 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 2.3
(+1.54/-1.39) x 10^21 cm^-2 (90% confidence).