[vsnet-grb-info 5449] GRB 071122: Swift detection of a burst

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7121
SUBJECT: GRB 071122: Swift detection of a burst
DATE:    07/11/22 01:45:10 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

M. Stamatikos (NASA/ORAU), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), P. J. Brown (PSU),
M. M. Chester (PSU), J. R. Cummings (NASA/UMBC),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
S. T. Holland (CRESST/USRA/GSFC), S. Immler (GSFC/UMCP),
J. A. Kennea (PSU), C. B. Markwardt (CRESST/GSFC/UMD),
F. E. Marshall (NASA/GSFC), C. Pagani (PSU),
K. L. Page (U Leicester), D. M. Palmer (LANL) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:

At 01:23:25 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 071122 (trigger=297114).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 276.581, +47.063 which is 
   RA(J2000)  =  18h 26m 20s
   Dec(J2000) = +47d 03' 47"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  As is typical with image triggers, there is
nothing obvious in the TDRSS lightcurve.  In these cases, the bursts often
have long duration. 

The XRT began observing the field at 01:25:45 UT, 140 seconds after the
BAT trigger. Using prompt downlinked data, we find an uncatalogued fading
X-ray source located at RA, Dec 276.6056, 47.0770 which is
   RA(J2000)  = 18 26 25.34
   Dec(J2000) = +47 04 37.2
with an uncertainty of 4.1 arcsec (radius, 90% containment). 
This location is 79 arcseconds from the BAT on-board position,
within the BAT error circle. The initial flux in the 2.5s image
was 6.9e-10 erg/cm2/s (0.2-10 keV). 

UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm)
filter starting 145 seconds after the BAT trigger. No afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The 3-sigma upper limit is 19.4 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.05. 

Burst Advocate for this burst is M. Stamatikos (michael AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)