GCN Circular 12598
Subject
GRB 111123A, Swift-BAT refined analysis
Date
2011-11-26T00:24:19Z (12 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori@milkyway.gsfc.nasa.gov>
H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
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 the recent telemetry downlink,
we report further analysis of BAT GRB 111123A (trigger #508319)
(Stamatikos, et al., GCN Circ. 12587). The BAT ground-calculated position is
RA, Dec = 154.845, -20.639 deg which is
RA(J2000) = 10h 19m 22.9s
Dec(J2000) = -20d 38' 19.9"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 81%.
The mask-weighted light curve shows two episodes. The first episode is starting
at T-10 sec, and peaking at T+10 sec with possible two or three overlapping pulses.
The second episode shows a gradual increases after the end of the initial episode,
peaks at T+150 sec, and ends at T+170 sec. The low level emission continues
up to T+~300 sec. T90 (15-350 keV) is 290.0 +- 88.1 sec (estimated error including
systematics).
The time-averaged spectrum from T-8.7 to T+481.3 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.68 +- 0.07. The fluence in the 15-150 keV band is 7.3 +- 0.3 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+146.30 sec in the 15-150 keV band
is 0.9 +- 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/508319/BA/