GRB 230310***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-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 230310***A*** (trigger #1159327)
(NAME, et al., GCN Circ. xxxx).  The BAT ground-calculated position is
RA, Dec = 272.155, -20.419 deg which is 
   RA(J2000)  =  18h 08m 37.3s 
   Dec(J2000) = -20d 25' 09.9" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 71%.
 
[Description about the mask-weighted light curve]
T90 (15-350 keV) is 0.45 +- 0.01 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.07 to T+0.50 sec fit by a simple
power-law model shows the power law index of 3.38 +- 0.00 (chi squared 969.11 for 57 d.o.f.).
The fluence in the 15-150 keV band is 7.5 +- 0.0 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T-0.29 sec in the 15-150 keV band
is 186.0 +- 0.0 ph/cm2/sec.
 
A single blackbody fit to the time-averaged spectrum shows the blackbody
temperature of 8.40 +- 0.00 keV (chi squared 201.91 for 57 d.o.f.).
A thermal bremsstrahlung model fit shows the temperature of 23.67 +- 0.00 keV
(chi squared 114.13 for 57 d.o.f.).  A double blackbody fit shows the lower temperature
of 6.24 +0.51 keV and the higher temperature of 11.68 +1.03 keV
(chi squared 42.02 for 55 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/1159327/BA/