GRB 210318***A***: Swift-BAT refined analysis
 
<somebody goes first>
<add the BA alphabetically>
S. D. Barthelmy (GSFC), 
J. R. Cummings (CPI),
H. A. Krimm (NSF),
S. Laha (GSFC/UMBC),
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-240 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 210318***A*** (trigger #1037335)
(NAME, et al., GCN Circ. xxxx).  The BAT ground-calculated position is
RA, Dec = 264.228, -35.822 deg which is 
   RA(J2000)  =  17h 36m 54.8s 
   Dec(J2000) = -35d 49' 18.0" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 95%.
 
[Description about the mask-weighted light curve]
T90 (15-350 keV) is 14.76 +- 0.46 sec (estimated error including systematics).
 
The time-averaged spectrum from T-9.00 to T+19.42 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.10 +- 0.13, 
and Epeak of 250.2 +- 178.8 keV (chi squared 39.28 for 0 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 1.0 +- 0.0 x 10^-05 erg/cm2
and the 1-sec peak flux measured from T+2.70 sec in the 15-150 keV band is
14.7 +- 0.4 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.31 +- 0.03 (chi squared 47.04 for 0 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/1037335/BA/