[vsnet-grb-info 15048] GRB 140529A: Swift-XRT afterglow detection.

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16342
SUBJECT: GRB 140529A: Swift-XRT afterglow detection.
DATE:    14/05/30 10:16:05 GMT
FROM:    Phil Evans at U of Leicester  <pae9 at leicester.ac.uk>

P.A. Evans (U. Leicester) and J.L. Racusin (GSFC) report on behalf of
the Swift-XRT team:

We have analysed 2.5 ks of XRT data for the ground-detected GRB 140529A
(Cummings, GCN. Circ. 16340) from 65.0 ks to 75.4 ks after the BAT
trigger time. The data are entirely in Photon Counting (PC) mode.  An
X-ray source is detected within the Swift/BAT error circle. Using 1098
s of PC mode data and 1 UVOT image, we find an enhanced XRT position
(using the XRT-UVOT alignment and matching UVOT field sources to the
USNO-B1 catalogue): RA, Dec = 228.78202, -41.05295 which is equivalent
to:

RA (J2000): 15h 15m 07.68s
Dec(J2000): -41d 03' 10.6"

with an uncertainty of 3.3 arcsec (radius, 90% confidence). This
position is 97 arcsec from the Swift/BAT position. 

In the first two spacecraft orbits, totalling 1.2 ks of data, the
source is present with a count rate of 0.012+/-0.004 ct/sec. In the
final orbit, with 1.3 ks of data the source is not detected, with a
3-sigma upper limit of 0.0045 ct/sec. We thus conclude that this was
the afterglow of GRB 140529A.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020383.

This circular is an official product of the Swift-XRT team.