T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), B. Sbarufatti (PSU),
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 210712A (trigger #1059881)
(Sbarufatti, et al., GCN Circ. 30447). The BAT ground-calculated position is
RA, Dec = 97.322, -35.376 deg which is
RA(J2000) = 06h 29m 17.3s
Dec(J2000) = -35d 22' 32.2"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 71%.
The mask-weighted light curve shows a series of peaks. The first is from roughly
T-40 to T-30. Then the strongest peak is from T-5 to T+15. This is followed by a
string of weaker peaks from T+20 to T+120. The spacecraft slewed away from
the burst location by T+700 sec. T90 (15-350 keV) is 136.41 +- 63.58 sec
(estimated error including systematics).
The time-averaged spectrum from -39.76 to 174.18 sec is best fit by a power law
with an exponential cutoff. This fit gives a photon index 1.00 +- 0.53,
and Epeak of 51.8 +- 11.6 keV (chi squared 70.95 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 3.0 +- 0.3 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+0.09 sec in the 15-150 keV band is
2.3 +- 0.3 ph/cm2/sec. A fit to a simple power law gives a photon index
of 1.85 +- 0.11 (chi squared 80.11 for 57 d.o.f.). All the quoted errors
are at the 90% confidence level.
The results of the batgrbproduct analysis are available at