TITLE:   GCN CIRCULAR
NUMBER:  18668
SUBJECT: GRB 151205A, Swift-BAT refined analysis
DATE:    15/12/06 05:09:17 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), D. M. Palmer (LANL), T. Sakamoto (AGU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
 
Using the data set from T-315 to T+934 sec from the recent telemetry downlinks,
we report further analysis of BAT GRB 151205A (trigger #666352)
(Cummings, et al., GCN Circ. 18657).  The BAT ground-calculated position is
RA, Dec = 229.291, 35.767 deg, which is
   RA(J2000)  =  15h 17m 09.7s 
   Dec(J2000) = +35d 46' 01.7" 
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 93%.
 
The mask-weighted light curve shows several overlapping peaks starting at
~T-10 sec, peaking at ~T+3 sec, with a long tail out to T+170 sec.
T90 (15-350 keV) is 62.8 +- 12.3 sec (estimated error including systematics).
 
The time-averaged spectrum from T-4.0 to T+69.5 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.17 +- 0.13.  The fluence in the 15-150 keV band is 1.4 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.98 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. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/666352/BA/