M. Stamatikos (GSFC/ORAU), S. D. Barthelmy (GSFC), W. Baumgartner
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), A. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato
P. Schady (MSSL-UCL), J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry
we report further analysis of BAT GRB 080913 (trigger #324561) (Schady,
GCN Circ. 8217). The BAT ground-calculated position is
RA, Dec = 65.741, -25.127 deg which is
RA(J2000) = 04h 22m 57.9s
Dec(J2000) = -25d 07' 38.6"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 39%.
The mask-weighted light curve shows multiple overlapping peaks, somewhat
smooth in character. T90 (15-350 keV) is 8 +- 1 sec (estimated error
The time-averaged spectrum from T-3.8 to T+5.2 sec is best fit by a
with an exponential cutoff. This fit gives a photon index 0.46 +- 0.70,
and Epeak of 93.1 +- 56.1 keV (chi squared 38.53 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 5.6 +- 0.6 x 10-07
and the 1-sec peak flux measured from T+0.11 sec in the 15-150 keV band is
1.4 +- 0.2 ph/cm2/sec. A fit to a simple power law gives a photon index
of 1.36 +- 0.15 (chi squared 44.56 for 57 d.o.f.). All the quoted errors
are at the 90% confidence level.
The results of the batgrbproduct analysis are available at