[vsnet-grb-info 6855] GRB 081029: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8447
SUBJECT: GRB 081029: Swift-BAT refined analysis
DATE:    08/10/29 12:48:10 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 081029 (trigger #332931)
(Sakamoto, et al., GCN Circ. 8435).  The BAT ground-calculated position is
RA, Dec = 346.776, -68.179 deg, which is 
   RA(J2000)  =  23h 07m 06.3s 
   Dec(J2000) = -68d 10' 43.4" 
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 58%.
 
The mask-weighted light curve shows a single relatively smooth peak
starting at ~T-50 sec, peaking at ~T+60 sec, and ending at ~T+300 sec.
T90 (15-350 keV) is 270 +- 45 sec (estimated error including systematics).
 
The time-averaged spectrum from T-35.6 to T+268.6 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.43 +- 0.18.  The fluence in the 15-150 keV band is 2.1 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+52.37 sec in the 15-150 keV band
is 0.5 +- 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/332931/BA/