TITLE:   GCN CIRCULAR
NUMBER:  19468
SUBJECT: GRB 160525B: Swift-BAT refined analysis
DATE:    16/05/26 04:07:57 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

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), M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 160525B (trigger #687522)
(Krimm, et al., GCN Circ. 19459).  The BAT ground-calculated position is
RA, Dec = 149.438, 51.197 deg, which is 
   RA(J2000)  =  09h 57m 45.2s 
   Dec(J2000) = +51d 11' 48.9" 
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 81%.
 
The mask-weighted light curve shows weak emission starting at ~T-1 sec,
the main emission from ~T0 to ~T+0.3 sec, and weak emission out to ~T+0.6 sec.
T90 (15-350 keV) is 0.29 +- 0.05 sec (estimated error including systematics).
 
The time-averaged spectrum from T+0.02 to T+0.33 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.89 +- 0.35.  The fluence in the 15-150 keV band is 3.2 +- 0.8 x 10^-8 erg/cm2.
The 1-sec peak photon flux measured from T-0.32 sec in the 15-150 keV band
is 0.9 +- 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/687522/BA/