[vsnet-grb-info 5683] GRB 080229, Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7338
SUBJECT: GRB 080229, Swift-BAT refined analysis
DATE:    08/03/01 00:15:19 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

C. Markwardt (GSFC/UMD), S. D. Barthelmy (GSFC), J. K. Cannizzo (NASA/UMBC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), K. McLean (GSFC/UMD), D. Palmer (LANL),
A. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+303 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080229 (trigger #304379)
(Cannizzo, et al., GCN Circ. 7335).  The BAT ground-calculated position is
RA, Dec = 228.220, -14.697 deg, which is 
   RA(J2000)  =  15h 12m 52.7s 
   Dec(J2000) = -14d 41' 50" 
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 18%.
 
The mask-weighted light curve shows an initial small peak starting
at ~T-3 sec, peaking at T_zero, and ending at ~T+12 sec.  Then there are
two smaller peaks centered on T+18 and T+28 sec.  Then comes two overlapping
large peaks on T+35 and T+39 sec with the latter tailing out to ~T+85 sec.
T90 (15-350 keV) is 64 +- 16 sec (estimated error including systematics).
 
The time-averaged spectrum from T-15.1 to T+64.9 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.91 +- 0.06.  The fluence in the 15-150 keV band is 9.0 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+40.36 sec in the 15-150 keV band
is 5.7 +- 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/304379/BA/