GCN Circular 13970
Subject
GRB 121117A, Swift-BAT refined analysis
Date
2012-11-17T21:31:41Z (11 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <james.r.cummings@nasa.gov>
J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), 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-61 to T+191 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 121117A (trigger #538696)
(Cummings, et al., GCN Circ. 13967). The BAT ground-calculated position is
RA, Dec = 31.617, 7.432 deg which is
RA(J2000) = 02h 06m 28.1s
Dec(J2000) = +07d 25' 55.6"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
The mask-weighted light curve shows a single FRED peak. Swift was close to
the SAA and BAT entered SAA mode about 250 seconds after the trigger. T90
(15-350 keV) is 30 +- 5 sec (estimated error including systematics).
The time-averaged spectrum from T+0.0 to T+158.6 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.16 +- 0.18. The fluence in the 15-150 keV band is 1.4 +- 0.2 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+7.06 sec in the 15-150 keV band
is 1.1 +- 0.1 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/538696/BA/