GCN Circular 20001

D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
P. A. Evans (U Leicester), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), J. P. Norris (BSU),
T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(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 161004A (trigger #715084)
(Evans, et al., GCN Circ. 19979
Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 263.127, -0.947 deg which is
    RA(J2000)  =  17h 32m 30.6s
    Dec(J2000) = -00d 56' 50.7"
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 92%.
  
The mask-weighted light curve shows a single peak starting at T-0.1 sec,
peaking at T+0.5 sec and ending at T+5 sec.  T90 (15-350 keV) is 1.08 +- 0.21 sec
(estimated error including systematics).
  
The time-averaged spectrum from T-0.11 to T+1.06 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.26 +- 0.33.  The fluence in the 15-150 keV band is 9.5 +- 1.6 x 10^-8 erg/cm2.
The 1-sec peak photon flux measured from T+0.06 sec in the 15-150 keV band
is 1.0 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

Due to a low signal-to-noise of the data, the lag analysis is not possible.
Therefore, it is not clear whether this burst belongs to a short GRB or not.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/715084/BA/