GCN Circular 4476
Subject
GRB 060109: Swift-BAT refined analysis
Date
2006-01-11T00:21:10Z (18 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori@milkyway.gsfc.nasa.gov>
D. Palmer (LANL), M. Ajello (MPE), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/ORAU), E. Fenimore (LANL), R. Fink (GSFC),
N. Gehrels (GSFC), D. Hullinger (UMD), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD),A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU),
G. Sato (ISAS), J. Tueller (GSFC),
on behalf of the Swift-BAT team:
Using the data set from T-299.2 to T+302.9 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 060109
(trigger #176620) (De Pasquale, et al., GCN 4455).
The BAT ground-calculated position
is (RA,Dec) = 282.739, 32.009 {18h 50m 57.3s, 32d 0' 32.6"} (deg; J2000)
+- 3.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 92%.
The mask-tagged lightcurve shows a double peak structure. The first peak has
a duration of ~20 sec. starting from T-2 sec. And the second peak has
a duration of ~40 sec. starting from T+75 sec.
T90 (15-350 keV) is (116 +- 3) sec (estimated error including systematics).
Over the full burst interval (T-0.4 to T+126.8 sec), the power law index of
the time-averaged spectrum is 1.96 +- 0.25. The fluence in the 15-150 keV
band is (6.4 +- 1.0) x 10^-07 erg/cm2. The 1-sec peak photon flux measured
from T+90.19 sec in the 15-150 keV band is (0.5 +- 0.1) ph/cm2/sec.
All the quoted errors are at the 90% confidence level.