[vsnet-grb-info 3311] GRB 060516: Refined analysis of the Swift-BAT burst

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5146
SUBJECT: GRB 060516:  Refined analysis of the Swift-BAT burst
DATE:    06/05/16 17:28:26 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <Scott at lheamail.gsfc.nasa.gov>

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

Using the data set from T-119 to T+183 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 060516 (trigger #210254)
(Parsons, et al., GCN 5144).  The BAT ground-calculated position is RA,Dec =
71.167,-18.096 deg {04h 44m 40.8s,-18d 05' 44"} (J2000) +- 3.3 arcmin,
(radius, sys+stat, 90% containment).  The partial coding was 79%.
The ground-calculated image significance in the 15-100 keV band is 12.3 sigma.

The mask-weighted lighcurve shows a long relatively smooth burst
starting at ~T-30 sec and extending out to T+130, mostly in the
15-50 keV band.  There is no significant emission in the >100 keV band.
T90 (15-350 keV) is 160 +- 20 sec (estimated error including systematics).
The long duration and smooth nature of the lightcurve could be an indication
of a high redshift burst.

The time-averaged spectrum from T-42.2 to T+134.0 is best fit by
a simple power-law model.  The power law index of the time-averaged
spectrum is 2.15 +- 0.24.  The fluence in the 15-150 keV band is
1.1 +- 0.2 x 10^-6 erg/cm2.  The 1-sec peak photon flux measured
from T+128.56 sec in the 15-150 keV band is 0.3 +- 0.2 ph/cm2/sec.
All the quoted errors are at the 90% confidence level.

Due to the Sun constraint, this GRB will not be observable by the
Swift XRT and UVOT instruments for >31 days.