GCN Circular 45703

T. Sakamoto (AGU), S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm
(NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC),
M. J. Moss (GSFC), D. M. Palmer (LANL), K. L. Page (U Leicester), T.
Parsotan (GSFC), D. Sadaula (GSFC/UMBC) (i.e. the Swift-BAT team):

Using the data set from T-61 to T+242 sec from the recent telemetry
downlink,
we report further analysis of BAT GRB 260922A (trigger #1512686)
(Page et al., GCN Circ. 45690
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 ).  The BAT ground-calculated position is
RA, Dec = 227.909, 14.216 deg which is
   RA(J2000)  =  15h 11m 38.1s
   Dec(J2000) = +14d 12' 57.8"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 21%.

The mask-weighted light curve shows a multi-pulse structures that starts at
~T-5 s and ends at ~T+80 s. The main peak occurs at ~T+1 s. T90 (15-350
keV) is 63.96 +- 12.79 sec (estimated error including systematics).

The time-averaged spectrum from T-4.90 to T+80.24 sec is best fit by a
simple power-law model.  The power law index of the time-averaged spectrum
is 1.42 +- 0.09.  The fluence in the 15-150 keV band is 4.7 +- 0.2 x 10^-06
erg/cm2. The 1-sec peak photon flux measured from T+0.72 sec in the 15-150
keV band is 5.7 +- 0.6 ph/cm2/sec.  All the quoted errors are at the 90%
confidence level.

The results of the batgrbproduct analysis are available at
https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1512686