GCN Circular 15710
Subject
GRB 140108A: Swift-BAT refined analysis
Date
2014-01-09T14:22:08Z (10 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), J. L. Racusin (NASA/GSFC),
T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 140108A (trigger #583338)
(Racusin, et al., GCN Circ. 15699). The BAT ground-calculated position is
RA, Dec = 325.129, 58.749 deg, which is
RA(J2000) = 21h 40m 30.9s
Dec(J2000) = +58d 44' 55.3"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 71%.
The mask-weighted light curve shows two main peaks; the first starting at
~T-25 sec, peaking at ~T+7 sec, and almost returns to background at T+20 sec.
The second peak starts at ~T+70 sec, peaks at ~T+77 sec, and ends at ~T+110 sec
with some weak emission (2-3 sigma) out to ~T+150 sec.
T90 (15-350 keV) is 97.8 +- 3.3 sec (estimated error including systematics).
The time-averaged spectrum from T-24.8 to T+103.3 sec (with 2.5 sec of missing
data in the middle of the 2nd peak) is best fit by a simple power-law model.
The power law index of the time-averaged spectrum is 1.60 +- 0.05.
The fluence in the 15-150 keV band is 6.3 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+6.49 sec in the 15-150 keV band
is 6.1 +- 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/583338/BA/