GCN Circular 4428
Subject
Swift-BAT trigger 175653 is not an astrophysical source
Date
2006-01-03T21:23:27Z (21 years ago)
From
Scott Barthelmy at NASA/GSFC <Scott@lheamail.gsfc.nasa.gov>
D. Grupe (PSU), S. Barthelmy (GSFC), T. Sakamoto (GSFC/NRC), M. Chester (PSU),
F. Marshall (GSFC), N. Gehrels (GSFC), D. Burrows (PSU), J. Kennea (PSU),
A. Retter (PSU)
on behalf of the Swift team:
We have analyzed the full BAT data set. Trigger 175653
(Grupe et al. 2006, GCN 4426) is due to (a) a chance fluctuation
in the rate domain, (b) superposed on a rising background
while entering the SAA, or (c) a chance fluctuation in the image domain.
The spacecraft slewed immediately to the BAT position, but
because the spacecraft was in the SAA, XRT only took a 2s image
which did not show any bright source. XRT started observing again
on 2006-January-03 05:19 UT about 75 minutes after the trigger.
This data set has a total observing time of 3.6 ks. We do not find
any source within the 3 arcmin BAT error circle. No afterglow candidate
was identified by UVOT's automated processing either.
Therefore we consider this trigger as false and not due to a GRB or
any astrophysical source.