GRB 230820***A***: Swift-BAT refined analysis
 
<somebody goes first>
<add the BA alphabetically>
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),
T. Sakamoto (AGU),
M. Stamatikos (OSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 230820***A*** (trigger #1186291)
(NAME, et al., GCN Circ. xxxx).  The BAT ground-calculated position is
RA, Dec = 84.313, 22.968 deg which is 
   RA(J2000)  =  05h 37m 15.2s 
   Dec(J2000) = +22d 58' 05.4" 
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 97%.
 
[Description about the mask-weighted light curve]
T90 (15-350 keV) is 106.00 +- 9.85 sec (estimated error including systematics).
 
The time-averaged spectrum from TTBD to TTBD sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.22 +- 0.10.  The fluence in the 15-150 keV band is 2.3 +- 0.1 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+1.00 sec in the 15-150 keV band
is 0.4 +- 0.1 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/1186291/BA/