GCN Circular 4747
Subject
GRB 060211B: Swift/BAT refined analysis
Event
Date
2006-02-11T23:52:58Z (19 years ago)
From
Hans Krimm at NASA-GSFC <krimm@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 (GSFC/UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU),
G. Sato (ISAS), on behalf of the Swift-BAT team:
Using the data set from T-61 to T+122 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 060211
(trigger #181156) (Mateos, et al., GCN 4739). The BAT
ground-calculated position is (RA,Dec) = 75.076, 14.954 deg
{5h 0m 18.2s, 14d 57' 14.5"} (J2000) +- 2.0 arcmin, (radius, sys+stat,
90% containment). The partial coding was 82%.
The mask-tagged light curve shows a multi-peak structure with possible
extended emission. The burst started at T-12 sec with a small peak, then a
4-sec long peak at T+0 that decays out to ~T+10 sec and low-level
emission out to T+20 sec. Additionally, there is a possible 10-sec wide weak
peak centered on T+100 sec and a possible faint precursor at T-22 sec.
T90 (15-350 keV) is (29 +- 5) sec (estimated error including systematics).
Since we do not have data past T+122 sec, we cannot say at this time anything
about the extended lightcurve. We expect that it will take at least
a day to get that data downlinked.
The time-averaged spectrum from T-11.0 to T+21.7 is best fit by
a simple power-law model. The power law index of the time-averaged spectrum
is 1.55 +- 0.21. The fluence in the 15-150 keV band is
(4.7 +- 0.6) x 10^-07 erg/cm2. The 1-sec peak photon flux measured from
T+1.84 sec in the 15-150 keV band is (0.7 +- 0.1) ph/cm2/sec.
All the quoted errors are at the 90% confidence level.