B. Sbarufatti (PSU), A. P. Beardmore (U Leicester), J.D. Gropp (PSU),
J. A. Kennea (PSU), H. A. Krimm (NSF), N. P. M. Kuin (UCL-MSSL),
S Laha (GSFC/UMBC/CRESST) and A. Tohuvavohu (U Toronto) report on
behalf of the Neil Gehrels Swift Observatory Team:
At 13:32:56 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 191122A (trigger=938899). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 54.296, -32.176 which is
RA(J2000) = 03h 37m 11s
Dec(J2000) = -32d 10' 32"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a single-peaked
structure with a duration of about 50 sec. The peak count rate
was ~1200 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 13:34:31.1 UT, 94.7 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 54.26926,
-32.18602 which is equivalent to:
RA(J2000) = 03h 37m 04.62s
Dec(J2000) = -32d 11' 09.7"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 89 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. No
spectrum from the promptly downlinked event data is yet available to
determine the column density.
The initial flux in the 2.5 s image was 1.89e-09 erg cm^-2 s^-1 (0.2-10
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 103 seconds after the BAT trigger. No credible 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 typical 3-sigma upper limit has been about 19.6 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
Burst Advocate for this burst is B. Sbarufatti (bxs60 AT psu.edu).
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/)