GCN Circular 20129

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC),
B. Mingo (U Leicester), J. P. Norris (BSU), 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+150 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 161104A (trigger #720568)
(Mingo, et al., GCN Circ. 20123
Not found
 
 
). The BAT ground-calculated position is
RA, Dec = 77.906, -51.447 deg which is
   RA(J2000)  =  05h 11m 37.3s
   Dec(J2000) = -51d 26' 49.7"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 99%.

The mask-weighted light curve shows a single spike that starts at at ~T-0.02,
peaks at ~T+0.02, and ends at~T+0.1. T90 (15-350 keV) is 0.1 +- 0.02 sec
(estimated error including systematics).

The time-averaged spectrum from T-0.0 to T+0.1 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 3.1 +- 0.5 x 10^-8 erg/cm2.
The 1-sec peak photon flux measured from T-0.46 sec in the 15-150 keV band
is 0.6 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

Using a 4-ms binned light curve, the lag analysis finds a lag of
2.0 +/- 8.0 ms for the 100-350 keV to 25-50 keV band,
and -3.5 +/- 8.0 ms for the 50-100 keV to 15-25 keV band.
These values are consistent with those of a short GRB.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/720568/BA/

[GCN OPS NOTE05nov16):  Per author's request, JN as was added
to the author list.]