[vsnet-grb-info 4783] GRB 070612B, Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6523
SUBJECT: GRB 070612B, Swift-BAT refined analysis
DATE:    07/06/12 20:39:42 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

J. Cummings (GSFC/UMBC), L. Barbier (GSFC), S. D. Barthelmy (GSFC),
E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL),
A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+962 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 070612B (trigger #282073)
(Grupe, et al., GCN Circ. 6511).  The BAT ground-calculated position is
RA, Dec = 261.716, -8.747 deg  which is 
   RA(J2000)  = 17h 26m 51.8s 
   Dec(J2000) = -8d 44' 48" 
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 17%.
 
The mask-weighted light curve shows a single roughly symetrical peak
starting at T-5 sec, peaking at T+0 sec, and ending at T+12 sec.
T90 (15-350 keV) is 13.5 +- 1 sec (estimated error including systematics).
 
The time-averaged spectrum from T-6.4 to T+10.3 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.55 +- 0.11.  The fluence in the 15-150 keV band is 1.7 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-0.16 sec in the 15-150 keV band
is 2.6 +- 0.4 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.