TITLE:   GCN CIRCULAR
NUMBER:  19302
SUBJECT: GRB 160411A: Swift-BAT refined analysis of the short burst
DATE:    16/04/12 12:52:25 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL),
T. Sakamoto (AGU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from the recent telemetry downlinks,
we report further analysis of BAT short GRB 160411A (trigger #682339)
(Page, et al., GCN Circ. 19279).  The BAT ground-calculated position is
RA, Dec = 349.370, -40.258 deg, which is 
   RA(J2000)  =  23h 17m 28.8s 
   Dec(J2000) = -40d 15' 30.3" 
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 27%.
 
The mask-weighted light curve shows two overlapping peaks starting at
~T+0.0 and ending at ~T+0.5 sec.  T90 (15-350 keV) is 0.36 +- 0.08 sec
(estimated error including systematics).
 
The time-averaged spectrum from T+0.06 to T+0.46 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.43 +- 0.28.  The fluence in the 15-150 keV band is 8.0 +- 1.8 x 10^-8 erg/cm2.
The 1-sec peak photon flux measured from T-0.24 sec in the 15-150 keV band
is 1.5 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/682339/BA/