M. Stamatikos (OSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), V. D'Elia (ASDC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+70 sec from recent telemetry downlinks, we report further analysis of BAT GRB 120403B (trigger #519256) (D'Elia, et al., GCN 13203). The BAT ground-calculated position is RA, Dec = 54.302, -89.029 deg, which is RA(J2000) = 03h 37m 12.6s Dec(J2000) = -89d 01' 45.1" with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 47%.

The mask-weighted light curve shows several overlapping peaks starting at ~T-5 sec and ending at ~T+10 sec. T90 (15-350 keV) is 7.3 +- 1.9 sec (estimated error including systematics).

The time-averaged spectrum from T-3.0 to T+5.3 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.79 +- 0.31. The fluence in the 15-150 keV band is 2.1 +- 0.4 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T+0.92 sec in the 15-150 keV band is 0.9 +- 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/519256/BA/

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