GCN Circular 17239
Subject
GRB 141225A: Swift-BAT refined analysis
Date
2014-12-26T14:29:58Z (9 years ago)
From
Hans Krimm at NASA-GSFC <hans.a.krimm@nasa.gov>
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), P. D'Avanzo (INAF-OAB), 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 downlink,
we report further analysis of BAT GRB 141225A (trigger #622476)
(D'Avanzo, et al., GCN Circ. 17229). The BAT ground-calculated position is
RA, Dec = 138.754, 33.774 deg which is
RA(J2000) = 09h 15m 01.1s
Dec(J2000) = +33d 46' 27.7"
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 26%.
The burst location first entered the BAT field of view at ~T-40 sec, during a
pre-planned slew. The mask-weighted light curve shows a single FRED-shaped
peak, beginning at T+5 sec, peaking at T+12 sec and returning to baseline level
by T+50 sec. T90 (15-350 keV) is 40.24 +- 7.04 sec sec (estimated error
including systematics).
The time-averaged spectrum from T+5.50 to T+50.68 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.32 +- 0.15. The fluence in the 15-150 keV band is 2.5 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+11.76 sec in the 15-150 keV band is
1.3 +- 0.4 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/622476/BA/