GCN Circular 30495

H. A. Krimm (NSF), S. D. Barthelmy (GSFC),

S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),

C. B. Markwardt (GSFC), D. M. Palmer (LANL),

T. Sakamoto (AGU), T. Sbarrato (INAF-OAB),

M. Stamatikos (OSU), T. N. Ukwatta (LANL)

(i.e. the Swift-BAT team):



Using the data set from T-239 to T+861 sec from the recent telemetry
downlink,

we report further analysis of BAT GRB 210723A (trigger #1061284)

(Sbarrato et al., GCN Circ. 30485
Not found
 
 
).  The BAT ground-calculated position is

RA, Dec = 121.723, -32.893 deg which is

   RA(J2000)  =  08h 06m 53.4s

   Dec(J2000) = -32d 53' 35.8"

with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).

The partial coding was 77%.



The mask-weighted light curve shows a single-pulse structure that

starts at ~T-5 s, peaks at ~T0, and ends at ~T+65 s. T90 (15-350 keV)

is 48.54 +- 3.50 sec (estimated error including systematics).



The time-averaged spectrum from T-4.59 to T+66.64 sec is best fit

by a power law with an exponential cutoff.  This fit gives a photon

index 0.85 +- 0.29, and Epeak of 88.2 +- 15.3 keV (chi squared 54.48

for 52 d.o.f.).  For this model the total fluence in the 15-150 keV band

is 5.3 +- 0.2 x 10^-6 erg/cm2 and the 1-sec peak flux measured from

T+2.68 sec in the 15-150 keV band is 3.1 +- 0.3 ph/cm2/sec.

A fit to a simple power law gives a photon index of 1.60 +- 0.06 (chi

squared 75.55 for 53 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/1061284/BA/