[vsnet-grb-info 4167] GRB 061222B, Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  5974
SUBJECT: GRB 061222B, Swift-BAT refined analysis
DATE:    06/12/22 20:38:24 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <jayc at milkyway.gsfc.nasa.gov>

L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC),
E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (BYU-Idaho),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL),
A. Parsons (GSFC), J. L. Racusin (PSU), 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-239.0 to T+903.1 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 061222 (trigger #252593)  
(Racusin, et al., GCN Circ. 5957).  The BAT ground-calculated position
is RA, Dec = 105.352, -25.865 deg which is 
   RA(J2000) = 7h 1m 24.6s 
   Dec(J2000) = -25d 51' 55.6" 
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).  
The partial coding was 16%.
 
The burst had a single gradual peak with several sub peaks.
T90 (15-350 keV) is 40 +- 5 sec (estimated error including systematics).
At this time, there is a gap in the downlinked data from T+480 sec to 
T+660 and T+720 to T+840 sec.  A further Circular will be issued if
burst activity is found in these intervals.
 
The time-averaged spectrum from T+35.1 to T+84.3 is best fit by 
a simple power-law model.  The power law index of the time-averaged 
spectrum is 1.98 +- 0.13.  The fluence in the 15-150 keV band is 
2.2 +- 0.2 x 10^-06 erg/cm2.  The 1-sec peak photon flux measured from 
T+59.16 sec in the 15-150 keV band is 1.5 +- 0.4 ph/cm2/sec.  All the 
quoted errors are at the 90% confidence level.