[vsnet-grb-info 17636] GRB 160221A: Swift-XRT afterglow detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19073
SUBJECT: GRB 160221A: Swift-XRT afterglow detection
DATE:    16/02/25 07:48:54 GMT
FROM:    Kim Page at U.of Leicester  <kpa at star.le.ac.uk>

A. Melandri (INAF-OAB), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), L.M.
McCauley (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U.
Leicester), 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
INTEGRAL-detected burst GRB 160221A (Mereghetti et al. GCN Circ.
19046). The observations now extend from T0+21.3 ks to T0+274.5 ks. The
source previously reported by Melandri et al. (GCN Circ. 19050),
"Source 1", is fading with 3-sigma significance, and is therefore
likely the GRB afterglow.  The position of this source is RA,
Dec=232.0895, -28.4551 which is equivalent to:

RA (J2000): 15:28:21.48
Dec(J2000): -28:27:18.4

with an uncertainty of 4.1 arcsec (radius, 90% confidence).  This
position is 80 arcsec from the INTEGRAL position.  The source is fading
with alpha >0.5.

The results of the XRT-team automatic analysis of the likely afterglow
are at http://www.swift.ac.uk/ToO_GRBs/00020600/index_1.php.
The results of the full analysis of the XRT observations are available
at http://www.swift.ac.uk/ToO_GRBs/00020600.

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