[vsnet-grb-info 4964] GRB 070729, Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6681
SUBJECT: GRB 070729, Swift-BAT refined analysis
DATE:    07/07/29 13:18:29 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

G. Sato (GSFC/ISAS), L. Barbier (GSFC), S. D. Barthelmy (GSFC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
C. Guidorzi (U.Bicocca&INAF-OAB), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/ORAU), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 070729 (trigger #286373)
(Guidorzi, et al., GCN Circ. 6678).  The BAT ground-calculated position is
RA, Dec = 56.296, -39.330 deg  which is 
   RA(J2000)  =   3h 45m 11.1s 
   Dec(J2000) = -39d 19' 47" 
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 65%.
 
The mask-weighted light curve shows two overlaping peaks starting at ~T-0.2 sec,
peaking at ~T+0.2 and ~T+0.8 sec, and ending at ~T+1.2 sec.
T90 (15-350 keV) is 0.9 +- 0.1 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.1 to T+1.1 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
0.96 +- 0.27.  The fluence in the 15-150 keV band is 1.0 +- 0.2 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.03 sec in the 15-150 keV band
is 1.0 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.