[vsnet-grb-info 16599] GRB 150527A: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17880
SUBJECT: GRB 150527A: Swift-BAT refined analysis
DATE:    15/05/27 16:47:04 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), P. A. Evans (U Leicester), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), 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-239 to T+711 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 150527A (trigger #641698)
(Evans, et al., GCN Circ. 17874).  The BAT ground-calculated position is
RA, Dec = 288.962, 4.195 deg, which is 
   RA(J2000)  =  19h 15m 50.9s 
   Dec(J2000) = +04d 11' 41.0" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 99%.
 
The mask-weighted light curves shows a multi-peak event starting at ~T-45 sec,
with the brightest peak at ~T-14, and ending at T+25 sec.
T90 (15-350 keV) is 112 +- 80 sec (estimated error including systematics).
 
The time-averaged spectrum from T-111.44 to T+16.56 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.69 +- 0.10.  The fluence in the 15-150 keV band is 3.1 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-7.94 sec in the 15-150 keV band
is 0.3 +- 0.2 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/641698/BA/