TITLE:   GCN CIRCULAR
NUMBER:  32970
SUBJECT: GRB 221120A: Swift-BAT refined analysis
DATE:    22/11/22 18:45:41 GMT
FROM:    Sibasish Laha at GSFC  <sibasish.laha@nasa.gov>

T. Sakamoto (AGU), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC),
M. Stamatikos (OSU) (i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 221120A (trigger #1141030)
(Eyles-Ferris et al., GCN Circ. 32955). The BAT ground-calculated position is
RA, Dec = 41.363, 43.241 deg which is
   RA(J2000)  =  02h 45m 27.1s
   Dec(J2000) = +43d 14' 26.5"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 97%.

The BAT  light curve shows several peaks within a duration of ~1 sec
T90 (15-350 keV) is 0.79 +- 0.16 sec (estimated error including systematics).

The time-averaged spectrum from T-0.60 to T+0.27 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
0.85 +- 0.27.  The fluence in the 15-150 keV band is 1.1 +- 0.2 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T-0.67 sec in the 15-150 keV band
is 1.2 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1141030/BA/