TITLE:   GCN CIRCULAR
NUMBER:  16063
SUBJECT: GRB 140331A: Swift-BAT refined analysis
DATE:    14/03/31 21:40:07 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), J. Tueller (GSFC), T. N. Ukwatta (MSU), B.-B. Zhang (UAH)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+827 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 140331A (trigger #594081)
(Zhang, et al., GCN Circ. 16049).  The BAT ground-calculated position is
RA, Dec = 134.860, 2.755 deg, which is 
   RA(J2000)  =  08h 59m 26.4s 
   Dec(J2000) = +02d 45' 19.5" 
with an uncertainty of 3.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 98%.
 
The mask-weighted light curve shows a long weak peak starting
at ~T+70 sec and ending at around T+350 sec.  T90 (15-350 keV)
is 209 +- 33 sec (estimated error including systematics).
 
The time-averaged spectrum from T87.28to T+321.14 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.01 +- 0.29.  The fluence in the 15-150 keV band is 6.7 +- 1.3 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+292.49 sec in the 15-150 keV band
is 0.31 +- 0.13 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/594081/BA/