[vsnet-grb-info 2655] GRB 060111B: Refined analysis of the Swift-BAT burst

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4492
SUBJECT: GRB 060111B:  Refined analysis of the Swift-BAT burst
DATE:    06/01/12 03:10:05 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <Scott at lheamail.gsfc.nasa.gov>

J. Tueller (GSFC), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cannizzo (GSFC-UMBC), L. Cominsky (Sonoma State U.),
J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hullinger (GSFC/UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/NRC),
G. Sato (ISAS)
on behalf of the Swift-BAT team:

Using the partial data set (T-60.2 to T+122.9 sec) from the recent telemetry
downlink, we report further analysis of BAT GRB 060111 (trigger #176918)
(Perri, et al., GCN 4487).  The BAT ground-calculated position is
RA,Dec = 286.460,+70.382 deg {19h 5m 50.4s,+70d 22' 54.0"} (J2000)
+- 1.6 arcmin, (radius, sys+stat, 90% containment).  The partial coding was 29%.
 
The mast-weighted lightcurve shows two peaks.  The first one starts at T-4 sec,
peaks at T+1, and extends out to T+28 sec.  The second, smaller peak starts
at T+53, peaks at T+55, and is over by T+62 sec.  T90 (15-350 keV) is
59 +- 1) sec (estimated error including systematics).
 
The power law index of the time-averaged spectrum (T-2 to T+63 sec)
is 1.04 +- 0.17.  The fluence in the 15-150 keV band is
(1.6 +- 0.1) x 10^-6 erg/cm2.  The 1-sec peak photon flux measured
from T+0.36 sec in the 15-150 keV band is 1.4 +- 0.3 ph/cm2/sec.
All the quoted errors are at the 90% confidence level.