[vsnet-grb-info 3407] GRB 060607: Swift-BAT Refined Analysis

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5242
SUBJECT: GRB 060607: Swift-BAT Refined Analysis
DATE:    06/06/07 19:41:47 GMT
FROM:    Hans Krimm at NASA-GSFC  <krimm at milkyway.gsfc.nasa.gov>

J. Tueller (GSFC), L. Barbier (GSFC),  S. Barthelmy (GSFC),
J. Cummings (GSFC/ORAU), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hullinger (BYU-Idaho), M. Koss (GSFC/UMD), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), D. Palmer (LANL),  A. Parsons (GSFC),
T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/JSPS/USRA), M. Stamatikos (GSFC/ORAU),
on behalf of the Swift-BAT team:

Using the data set from T-119.6 to T+182.5 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 060607
(trigger #213823)  (Ziaeepour, et al., GCN 5233).  The BAT 
ground-calculated position
is (RA,Dec) = 329.712, -22.500 deg {21h 58m 50.8s, -22d 30' 0.0"} (J2000)
+- 0.8 arcmin, (radius, sys+stat, 90% containment).  The partial 
coding was 99%.

The mask weighted light curve consists of two overlapping FRED peaks from
T-5 sec to T+40 sec.  There is a second double peaked structure between
T+95 sec and T+105 sec. T90 (15-350 keV) is 100 +- 5 sec
(estimated error including systematics).

The time-averaged spectrum from T-14.1 to T+104.5 is best fit by
a simple power-law model.   The power law index of the time-averaged
spectrum is 1.45 +- 0.07. The fluence in the 15-150 keV band is
2.6 +- 0.1 x 10^-06 erg/cm2.  The 1-sec peak photon flux measured
from T-0.97 sec in the 15-150 keV band is 1.4 +- 0.1 ph/cm2/sec.
All the quoted errors are at the 90% confidence level.

Using the redshift of 3.082 reported by Ledoux et al (GCN 5237) and a
cosmology of Omega_M - 0.3, Omega_lamba = 0.7 H0 = 65, we find
Eiso (1-1000 keV in the rest frame) to be 1.1 X 10^53 ergs.  This is based
on an extrapolation of the BAT power law fit into the corresponding
observer energy band.