TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5551
SUBJECT: GRB 060908, Swift-BAT refined analysis
DATE:    06/09/08 14:27:06 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

D. Palmer (LANL), L. Barbier (GSFC), S. D. Barthelmy (GSFC),
J. Cummings (GSFC/UMD), P. A. Evans (U Leicester), E. Fenimore (LANL),
N. Gehrels (GSFC), D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU),
G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC)
on behalf of the Swift-BAT team:
 
Using the data set from T-240 to T+302 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 060908 (trigger #228581)
(Evans, et al., GCN Circ. 5544).  The BAT ground-calculated position is
RA,Dec = 31.820, 0.330 deg {2h 7m 16.8s,+0d 19' 48.9"} (J2000) +- 1.5 arcmin,
(radius, sys+stat, 90% containment).  The partial coding was 46%.
 
The lighcurve has 3 overlapping peaks starting at ~T-12 sec then briefly
returning to background at T+6 sec.  The second peak has a maximium
at T+10 sec and ends at T+14 sec.  T90 (15-350 keV) is 19.3 +- 0.3 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-17.5 to T+15.1 is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.33 +- 0.07.  The fluence in the 15-150 keV band is 2.9 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.97 sec in the 15-150 keV band
is 3.2 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence level.