GCN Circular 30536

D. M. Palmer (LANL), S. D. Barthelmy (GSFC),
M. G. Bernardini (INAF-OAB), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(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 210726A (trigger #1061687)
(Bernardini et al., GCN Circ. 30523
Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 193.333, 19.211 deg which is
   RA(J2000)  =  12h 53m 19.9s
   Dec(J2000) = +19d 12' 38.9"
with an uncertainty of 2.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The mask-weighted light curve shows a short spike that starts at ~T0,
peaks at ~T+0.2 s, and ends at ~T+0.4 s. Some tail emission from the
raw light curves was mentioned in the original circular (Bernardini et al.,
GCN Circ. 30523
Not found
 
 
), and this potential weak tail can be seen in the 1-s
binned
light curve (15-350 keV) as well. However, image analyses from ~T+0.5 s
to ~T+2 s do not find any significant detections that are >~ 2 sigma.
Therefore, this signal is also consistent with noise fluctuation.
T90 (15-350 keV) is 0.39 +- 0.11 sec (estimated error including
systematics).

The time-averaged spectrum from T-0.00 to T+0.42 sec is best fit by
a simple power-law model.  The power law index of the time-averaged
spectrum is 1.54 +- 0.47.  The fluence in the 15-150 keV band is
4.5 +- 1.1 x 10^-8 erg/cm2. The 1-sec peak photon flux measured from
T-0.29 sec in the 15-150 keV band is 0.7 +- 0.3 ph/cm2/sec.
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/1061687/BA/