GCN Circular 4217
Subject
GRB 051109: Swift-BAT refined analysis
Date
2005-11-09T04:25:01Z (18 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori@milkyway.gsfc.nasa.gov>
E. Fenimore (LANL), L. Angelini (GSFC-JHU), L. Barbier (GSFC),
S. Barthelmy (GSFC), J. Cummings (GSFC/NRC), N. Gehrels (GSFC),
J. Greiner (MPE), D. Hullinger (UMD), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/NRC), G. Sato (ISAS), J. Tueller (GSFC),
on behalf of the Swift-BAT team:
Using the data set from T-60 to T+70 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 051109
(trigger #163136) (Tagliaferri, et al., GCN 4213). The BAT
ground-calculated position is
(RA,Dec) = 330.295, +40.836 {22h 01m 10.7s, +40d 50' 10.5"} [deg; J2000]
+-2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 9%.
The lightcurve has two peaks. The initial strong peak starts at
T-5 sec with a duration of 20 sec. The second weaker peak starts
at T+21 sec. with a duration of 20 sec. T90 (15-350 keV) is (36 +- 2) sec
(estimated error including systematics).
The power law index of the time-averaged spectrum is 1.5 +- 0.2.
The fluence in the 15-150 keV band is (2.1 +- 0.3) x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T0+0.4 sec in the 15-150 keV
band is (3.7 +- 0.7) ph/cm2/sec. All the quoted errors are at the 90%
confidence level.