[vsnet-grb-info 13374] GRB 130527A: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14708
SUBJECT: GRB 130527A: Swift-BAT refined analysis
DATE:    13/05/28 14:55:43 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), B.P. Gompertz (U Leicester),
H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), G. Sato (ISAS),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-700 to T+302 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 130527A (trigger #556753)
(Gompertz, et al., GCN Circ. 14703).  The BAT ground-calculated position is
RA, Dec = 309.282, -24.726 deg, which is 
   RA(J2000)  =  20h 37m 07.6s 
   Dec(J2000) = -24d 43' 35.1" 
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 10%.
 
The mask-weighted light curve shows many overlapping peakst starting
at ~T-10 sec, peaking at ~T+1 sec, and ending at ~T+170 sec.
T90 (15-350 keV) is 44 +- 16 sec (estimated error including systematics).
 
The time-averaged spectrum from T-2.9 to T+90.7 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.25 +- 0.06.  The fluence in the 15-150 keV band is 1.2 +- 0.04 x 10^-5 erg/cm2.
The 1-sec peak photon flux measured from T+0.06 sec in the 15-150 keV band
is 20.1 +- 1.4 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/556753/BA/