T. Ukwatta (GWU), 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), A. Parsons (GSFC), T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+130 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 080725 (trigger #317888)
(Krimm, et al., GCN Circ. 8014). The BAT ground-calculated position is
RA, Dec = 121.699, -13.984 deg which is
RA(J2000) = 08h 06m 47.7s
Dec(J2000) = -13d 59' 03.4"
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 42%.
The mask-weighted light curve starts with a short, faint precursor from
T-105 to T-100 sec. The main emission peak begins at T-20 sec and rises
to a peak at T+2 sec. There is a second peak at T+13 sec, and the
emission falls to background levels by T+25 sec. T90 (15-350 keV) is 120
(+5, -75) sec (estimated error including systematics). The spacecraft
slewed away from the burst location starting at T+100 sec, so there is
no data beyond T+130 sec.
The time-averaged spectrum from T-105.5 to T+51.8 sec is best fit by a
simple power-law model. The power law index of the time-averaged
spectrum is 1.50 +- 0.10. The fluence in the 15-150 keV band is 3.7 +-
0.2 x 10-6 erg/cm2. The 1-sec peak photon flux measured from T+3.54 sec
in the 15-150 keV band is 2.3 +- 0.3 ph/cm2/sec. All the quoted errors
are at the 90% confidence level.
The results of the batgrbproduct analysis are available at