[vsnet-grb-info 2400] GRB 051109B: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4237
SUBJECT: GRB 051109B: Swift-BAT refined analysis
DATE:    05/11/09 21:44:23 GMT
FROM:    Takanori Sakamoto at NASA/GSFC  <takanori at milkyway.gsfc.nasa.gov>

D. Hullinger (UMD), L. Barbier (GSFC), S. Barthelmy (GSFC), 
J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC), 
D. Hinshaw (GSFC-SPSYS), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), 
P. Meszaros (PSU), 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-300 to T+300 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 051109B 
(trigger #163170)  (Tagliaferri, et al., GCN 4222).  
The BAT ground-calculated position is 
(RA,Dec) = 345.468, +38.666 {23h 1m 52.3s, 38d 39' 58"} [deg; J2000]
+-2.0 arcmin, (radius, sys+stat, 90% containment).  
The partial coding was 90%.  

The light curve has a single peak.  There is no strong emission in 
the 100-350 keV band.  T90 (15-350 keV) is (15 +- 1) sec 
(estimated error including systematics).  

The power law index of the time-averaged spectrum is 1.96 +- 0.25.  
The fluence in the 15-150 keV band is (2.7 +- 0.4) x 10^-7 erg/cm2.  
The 1-sec peak photon flux measured from T0+0.24 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.