W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
P. A. Evans (U Leicester), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
Using the data set from T-61 to T+242 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 140304A (trigger #590206)
(Evans, et al., GCN Circ. 15915). The BAT ground-calculated position is
RA, Dec = 30.653, 33.480 deg, which is
RA(J2000) = 02h 02m 36.8s
Dec(J2000) = +33d 28' 47.4"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 74%.
The mask-weighted light curve shows several overlapping peaks starting
at ~T-10 sec, peaking at ~T+10 sec, and ending at ~T+30 sec.
T90 (15-350 keV) is 15.6 +- 1.9 sec (estimated error including systematics).
The time-averaged spectrum from T-3.94 to T+15.77 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.29 +- 0.08. The fluence in the 15-150 keV band is 1.2 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+10.22 sec in the 15-150 keV band
is 1.7 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence
The results of the batgrbproduct analysis are available at