[vsnet-grb-info 12262] GRB 120815A: Swift-XRT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13647
SUBJECT: GRB 120815A: Swift-XRT observations
DATE:    12/08/15 03:47:18 GMT
FROM:    Phil Evans at U of Leicester  <pae9 at star.le.ac.uk>

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

The XRT began observing the field of GRB 120815A at 02:58:45.5 UT,
2686.8 seconds after the BAT trigger. Using promptly downlinked data we
find an uncatalogued X-ray source located at RA, Dec 273.95896,
-52.12978 which is equivalent to:
   RA(J2000)  = 18h 15m 50.15s
   Dec(J2000) = -52d 07' 47.2"
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This
location is 17 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 (8.55 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 1.6
(+1.61/-1.45) x 10^21 cm^-2 (90% confidence).