GCN Circular 14067
Subject
GRB 121211A: Swift-BAT refined analysis
Date
2012-12-12T13:36:02Z (11 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), V. Mangano (INAF-IASFPA), D. M. Palmer (LANL),
T. Sakamoto (AGU), G. Sato (ISAS), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 121211A (trigger #541200)
(Mongano, et al., GCN Circ. 14057). The BAT ground-calculated position is
RA, Dec = 195.575, 30.173 deg, which is
RA(J2000) = 13h 02m 18.0s
Dec(J2000) = +30d 10' 24.4"
with an uncertainty of 4.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 23%.
The mask-weighted light curve shows a peak starting at ~T-5 sec, peaking at
~T+2 sec, and returning to baseline at ~T+5 sec. Then a second set of peaks
starts at ~T+20 with the main emission from T+105 to ~T+200 sec.
T90 (15-350 keV) is 182 +- 39 sec (estimated error including systematics).
The time-averaged spectrum from T-0.48 to T+196.77 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
2.36 +- 0.26. The fluence in the 15-150 keV band is 1.3 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.07 sec in the 15-150 keV band
is 1.0 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/541200/BA/