[vsnet-grb-info 9468] GRB 100628A: Chandra observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10942
SUBJECT: GRB 100628A:  Chandra observations
DATE:    10/07/06 22:27:15 GMT
FROM:    Edo Berger at Harvard  <eberger at cfa.harvard.edu>

E. Berger (Harvard) reports:

"We observed the field of the short GRB 100628 (GCN 10895) with the
Chandra X-ray Observatory starting on 2010 July 2.79 UT for a total of
19.8 ksec.  Within the XRT error circle (GCN 10907) we detect a single
point source at the following coordinates (J2000):

       RA = 15:03:53.33
       DEC = -31:39:50.5

This object is coincident with the bright core of the galaxy "G1"
(GCNs 10902,10908).  The flux of the object is about 4.8e-14
erg/cm^2/s, in good agreement with the flux measured with the
Swift/XRT of about 4.6e-14 erg/cm^2/s (see Swift/XRT GRB lightcurve
repository: http://www.swift.ac.uk/xrt_curves/00426114/).  Given the
position of the source and its constant flux we conclude that it is
due to AGN activity and is therefore not related to GRB 100628 (see
also GCN 10941).

Furthermore, we do not detect any emission at the location of the new
and possibly fading XRT source (GCN 10941) to a 3-sigma limit of
<5e-15 erg/cm^2/s, about a factor of 15 times fainter than the initial
XRT detection.

We thank Harvey Tananbaum and the CXO scheduling staff for rapidly
approving and executing this observation."