[vsnet-grb-info 6590] GRB 080906, Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8196
SUBJECT: GRB 080906, Swift-BAT refined analysis
DATE:    08/09/07 17:40:23 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

M. Stamatikos (GSFC/ORAU), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),
D. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
J. Tueller (GSFC), T. Ukwatta (GWU), L. Vetere (PSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080906 (trigger #323984)
(Vetere, et al., GCN Circ. 8186).  The BAT ground-calculated position is
RA, Dec = 228.055, -80.540 deg, which is 
   RA(J2000)  =  15h 12m 13.3s 
   Dec(J2000) = -80d 32' 24.9" 
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 58%.
 
The mask-weighted light curve shows a roughly symmetrical peak starting
at ~T-100 sec, peaking around T+10 sec, and tailing off to about T+100 sec.
T90 (15-350 keV) is 147 +- 21 sec (estimated error including systematics).
 
The time-averaged spectrum from T-105 to T+104 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.59 +- 0.09.  The fluence in the 15-150 keV band is 3.5 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-0.06 sec in the 15-150 keV band
is 1.0 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/323984/BA/