T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), E. Troja (NASA/GSFC/UMCP),
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 161117B (trigger #722642)
(Troja, et al., GCN Circ. 20182). The BAT ground-calculated position is
RA, Dec = 298.830, -67.681 deg which is
RA(J2000) = 19h 55m 19.1s
Dec(J2000) = -67d 40' 51.8"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 43%.
The mask-weighted light curve shows a complex structure. The first set of peaks
begins around T-10 sec, peaks at T+2 and fades by T+10 sec. The second set
of peaks begins around T+92 sec, peaks at T+102 sec and fades nearly to
background by T+115 sec. This is when the third set of peaks begins to rise,
which peaks at T+T+135 sec and fades by T+160 sec. All of these peak
structures have multiple sub-peaks. T90 (15-350 keV) is 152.51 +- 3.37 sec
(estimated error including systematics).
The time-averaged spectrum from T-8.32 to T+157.44 sec is best fit by a power law
with an exponential cutoff. This fit gives a photon index 1.39 +- 0.28,
and Epeak of 37.5 +- 5.5 keV (chi squared 39.62 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 6.0 +- 0.2 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+133.80 sec in the 15-150 keV band is
6.0 +- 0.3 ph/cm2/sec. A fit to a simple power law gives a photon index
of 2.14 +- 0.06 (chi squared 64.42 for 57 d.o.f.). All the quoted errors
are at the 90% confidence level.
The results of the batgrbproduct analysis are available at