GRB 230720***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-74 to T+603 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 230720***A*** (trigger #1180060)
(NAME, et al., GCN Circ. xxxx).  The BAT ground-calculated position is
RA, Dec = 47.605, 59.765 deg which is 
   RA(J2000)  =  03h 10m 25.3s 
   Dec(J2000) = +59d 45' 54.9" 
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 64%.
 
[Description about the mask-weighted light curve]
T90 (15-350 keV) is 112.00 +- 0.00 sec (estimated error including systematics).
 
The time-averaged spectrum from T+0.00 to T+112.00 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.05 +- 0.94, 
and Epeak of 21.3 +- 12.8 keV (chi squared 44.80 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 1.8 +- 0.2 x 10^-06 erg/cm2
and the 1-sec peak flux measured from T+0.00 sec in the 15-150 keV band is
0.4 +- 0.0 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 2.57 +- 0.17 (chi squared 53.23 for 57 d.o.f.).  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/1180060/BA/