T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), (i.e. the Swift-BAT team):
Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180113A (trigger #804999)
(Ukwatta et al., GCN Circ. 22325). The BAT ground-calculated position is
RA, Dec = 19.211, 68.682 deg which is
RA(J2000) = 01h 16m 50.7s
Dec(J2000) = +68d 40' 55.9"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 75%.
The mask-weighted light curve shows some weak emissions that starts at ~T-15 s,
followed by the main structure with several overlapping pulses from ~ T0 to ~T+15 s,
and a weak tail that lasts until ~T+70 s. T90 (15-350 keV) is 64 +- 16 sec
(estimated error including systematics).
The time-averaged spectrum from T-12.98 to T+67.02 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.08 +- 0.06. The fluence in the 15-150 keV band is 4.8 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+10.52 sec in the 15-150 keV band
is 2.5 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence
The results of the batgrbproduct analysis are available at