[vsnet-grb-info 16706] GRB 150622A: Swift-XRT afterglow detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17987
SUBJECT: GRB 150622A: Swift-XRT afterglow detection
DATE:    15/07/02 07:40:41 GMT
FROM:    Kim Page at U.of Leicester  <kpa at star.le.ac.uk>

D.N. Burrows (PSU), J.A. Kennea (PSU), V. Mangano (PSU), J.P. Osborne
(U. Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester), A.
Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC) and P.A.
Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has conducted further observations of the field of the
MAXI-detected burst GRB 150622A (Kawakubo et al. GCN Circ. 17952). The
observations now extend from T0+14.7 ks to T0+843.1 ks. The source
previously reported by Burrows et al. (GCN Circ. 17954), "Source 1", is
fading with 3-sigma significance, and is therefore likely the GRB
afterglow. Using 483 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 = 252.45633, -52.85017
which is equivalent to:

RA (J2000): 16h 49m 49.52s
Dec(J2000): -52d 51' 00.6"

with an uncertainty of 4.1 arcsec (radius, 90% confidence). This
position is 16.3 arcmin from the MAXI position.  The source is fading
with alpha >0.4.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020534.
The results of the full analysis of the tiled XRT observations are
available at http://www.swift.ac.uk/xrt_products/TILED_GRB00046.

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