TITLE:   GCN CIRCULAR
NUMBER:  20100
SUBJECT: GRB 161022A: Swift-BAT refined analysis
DATE:    16/10/22 22:02:21 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+737 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 161022A (trigger #718655)
(Stamatikos, et al., GCN Circ. 20087).  The BAT ground-calculated position is
RA, Dec = 128.988, 54.366 deg, which is 
   RA(J2000)  =  08h 35m 57.2s 
   Dec(J2000) = +54d 21' 57.8" 
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 14%.
 
The mask-weighted light curve shows a few overlapping peaks starting at ~T-1 sec,
peaking at ~T+2 sec, an ending at ~T+15 sec.
T90 (15-350 keV) is 7.3 +- 1.0 sec (estimated error including systematics).
 
The time-averaged spectrum from T+0.53 to T+8.24 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.14 +- 0.21.  The fluence in the 15-150 keV band is 7.5 +- 1.0 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+2.13 sec in the 15-150 keV band
is 1.6 +- 0.4 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/718655/BA/