[vsnet-grb-info 20789] GRB 180704A: Swift-XRT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22887
SUBJECT: GRB 180704A: Swift-XRT observations
DATE:    18/07/04 07:18:52 GMT
FROM:    Phil Evans at U of Leicester  <pae9 at leicester.ac.uk>

D.N. Burrows (PSU), J.A. Kennea (PSU), M. Perri (ASDC), G. Tagliaferri
(INAF-OAB), 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 180704A at 06:26:11.9 UT,
2969.1 seconds after the BAT trigger. Using promptly downlinked data we
find an uncatalogued X-ray source with an enhanced position: RA, Dec
32.6592, 69.9641 which is equivalent to:
   RA(J2000)  = 02h 10m 38.22s
   Dec(J2000) = +69d 57' 50.7"
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This
location is 63 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 consistent with the Galactic value of 4.92
x 10^21 cm^-2 (Willingale et al. 2013).