GCN Circular 18754
Subject
GRB 151228A: Swift-BAT refined analysis
Date
2015-12-29T15:37:40Z (8 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlinks,
we report further analysis of BAT GRB 151228A (trigger #668543)
(Ukwatta, et al., GCN Circ. 18731). The BAT ground-calculated position is
RA, Dec = 214.017, -17.665 deg, which is
RA(J2000) = 14h 16m 04.0s
Dec(J2000) = -17d 39' 52.7"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
The mask-weighted light curve shows a single spike starting at ~T-0.05,
peaking at ~T+0.03, and ending at ~T+0.3. T90 (15-350 keV) is
0.27 +- 0.01 sec (estimated error including systematics).
The time-averaged spectrum from T-0.036 to T+0.276 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
0.85 +- 0.20. The fluence in the 15-150 keV band is 8.4 +- 1.1 x 10^-8 erg/cm2.
The 1-sec peak photon flux measured from T-0.38 sec in the 15-150 keV band
is 0.9 +- 0.2 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/668543/BA/