[vsnet-grb-info 4619] GRB 070506, Swift-BAT Refined Analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6376
SUBJECT: GRB 070506, Swift-BAT Refined Analysis
DATE:    07/05/06 16:38:17 GMT
FROM:    Michael Stamatikos at GSFC  <michael at milkyway.gsfc.nasa.gov>

L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E.
Fenimore (LANL), N. Gehrels (GSFC), 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) on behalf
of the Swift-BAT team:
 
Using the data set from T-239 to T+963 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 070506 (trigger #278693)
(Pagani, et al., GCN Circ. 6375).  The BAT ground-calculated position is RA,
Dec = 347.203, 10.711 deg which is 
   RA(J2000) = 23h 8m 48.8s 
   Dec(J2000) = 10d 42' 40.3" 
with an uncertainty of 2 arcmin, (radius, sys+stat, 90% containment). The
partial coding was 96%.
 
The mask-weighted light curve begins to rises at ~T+2 sec, peaks at ~T+6.5
sec, and returns to the background level by ~T+10 sec, with trivial emission
above 100 keV. T90 (15-350 keV) is 4.3 +- 0.3 sec (estimated error including
systematics).
 
The time-averaged spectrum from T+4.1 to T+9.0 is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is 1.72
+- 0.17. The fluence in the 15-150 keV band is 2.1 +- 0.2 x 10^-7 erg/cm^2.
The 1-sec peak photon flux measured from T+6.16 sec in the 15-150 keV band
is 1.0 +- 0.1 ph/cm^2/sec.  All the quoted errors are at the 90% confidence
level.