W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. H. Siegel (PSU)
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 111225A (trigger #510341)
(Siegel, et al., GCN Circ. 12720). The BAT ground-calculated position is
RA, Dec = 13.158, 51.573 deg which is
RA(J2000) = 00h 52m 37.9s
Dec(J2000) = +51d 34' 21.8"
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 93%.
The mask-weighted light curve shows a FRED like structure with the emission
starting at ~T-15 sec, peaking at ~T-5 sec and ending at ~T+150 sec.
T90 (15-350 keV) is 106.8 +- 26.7 sec (estimated error including systematics).
The time-averaged spectrum from T-14.28 to T+111.24 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.70 +- 0.15. The fluence in the 15-150 keV band is 1.3 +- 0.1 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T-4.40 sec in the 15-150 keV band
is 0.7 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence
The results of the batgrbproduct analysis are available at