GCN Circular 5589
Subject
GRB 060923, Swift-BAT refined analysis
Date
2006-09-23T10:28:17Z (18 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
J. Tueller (GSFC) L. Barbier (GSFC), S. D. Barthelmy (GSFC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
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)
on behalf of the Swift-BAT team:
Using the data set from T-240 to T+879 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 060923 (trigger #230662)
(Stamatikos, et al., GCN Circ. 5583). The BAT ground-calculated position
is RA,Dec = 254.623, 12.341 deg {16h 58m 29.6s, 12d 20' 28.1"} (J2000)
+- 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 33%.
The burst started with a 6-sec wide peak at T-42 sec. The main peak starts
at T-5 sec, peaks at T+1 sec, and ends at T+20 sec. There is a possible
third peak at T+19 sec. T90 (15-350 keV) is 51.7 +- 1 sec
(estimated error including systematics).
The time-averaged spectrum from T-42.3 to T+11.5 is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.69 +- 0.23. The fluence in the 15-150 keV band is 8.7 +- 1.3 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.03 sec in the 15-150 keV band
is 1.3 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level.