J. R. Cummings (CPI), S. D. Barthelmy (GSFC),
P. A. Evans (U Leicester), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(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 181213A (trigger #876016)
(Evans et al., GCN Circ. 23525). The BAT ground-calculated position is
RA, Dec = 248.210, 78.500 deg which is
RA(J2000) = 16h 32m 50.5s
Dec(J2000) = +78d 30' 00.7"
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 21%.
The mask-weighted light curve shows a multi-peaked structure that starts
at ~T-1 s and ends at ~T+16 s. Note that the burst went out of the BAT
field of view at ~T+100 s. T90 (15-350 keV) is 15.31 +- 1.24 sec (estimated
error including systematics).
The time-averaged spectrum from T-0.70 to T+15.94 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.57 +- 0.20. The fluence in the 15-150 keV band is 1.5 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.16 sec in the 15-150 keV band
is 2.1 +- 0.6 ph/cm2/sec. All the quoted errors are at the 90% confidence
The results of the batgrbproduct analysis are available at