[vsnet-grb-info 3787] GRB 060926, Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5621
SUBJECT: GRB 060926, Swift-BAT refined analysis
DATE:    06/09/26 23:19:19 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

J. Cummings (GSFC/UMBC), L. Barbier (GSFC), S. D. Barthelmy (GSFC),
E. Fenimore (LANL), N. Gehrels (GSFC), S. T. Holland (GSFC/USRA),
D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU),
G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC)
on behalf of the Swift-BAT team:
 
Using the data set from T-119 to T+183 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 060926 (trigger #231231)
(Holland, et al., GCN Circ. 5612).  The BAT ground-calculated position
is RA,Dec = 263.925, 13.039 deg {17h 35m 41.9s, 13d 2' 21.5"} (J2000)
+- 1.4 arcmin, (radius, sys+stat, 90% containment).  The partial coding was 94%.
 
The mask-weighted lightcuve shows a single FRED peak starting at T-1 sec,
peaking at T+1 sec, and ending approximately at T+10 sec.
T90 (15-350 keV) is 8.0 +- 0.1 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.1 to T+8.6 is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.54 +- 0.23.  The fluence in the 15-150 keV band is 2.2 +- 0.3 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.38 sec in the 15-150 keV band
is 1.1 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence level.