[vsnet-grb-info 4721] GRB 070529, Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6468
SUBJECT: GRB 070529, Swift-BAT refined analysis
DATE:    07/05/29 18:10:23 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

A. Parsons (GSFC), L. Barbier (GSFC), S. D. Barthelmy (GSFC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
S. T. Holland (CRESST/GSFC/USRA), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/ORAU),
G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
T. Ukwatta (GWU)
on behalf of the Swift-BAT team:
 
Using the data set from T-119 to T+283 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 070529 (trigger #280706)
(Holland, et al., GCN Circ. 6466).  The BAT ground-calculated position is
RA, Dec = 283.725, 20.648 deg  which is 
   RA(J2000)  = 18h 54m 54.0s 
   Dec(J2000) = 20d 38' 54" 
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 16%.
 
The mask-weighted lightcurve shows multiple overlapping peaks
starting at T_0 and lasting out T+120 sec.  There is a possible (~4 sigma)
10-sec peak at ~T-55 sec.  T90 (15-350 keV) is 109 +- 3 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-1.2 to T+120.9 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.38 +- 0.16.  The fluence in the 15-150 keV band is 2.6 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+2.02 sec in the 15-150 keV band
is 1.4 +- 0.4 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.