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GCN Circular 11500

GRB 101225A, Swift-BAT refined analysis
2010-12-26T17:20:01Z (13 years ago)
Hans Krimm at NASA-GSFC <>
D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), J. L. Racusin (NASA/GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):

Using the data set from T-131 to T+1366 sec from the recent telemetry downlink,
we report further analysis of Swift/BAT GRB 101225A (trigger #441015)
(Racusin, et al., GCN Circ. 11493).  The BAT ground-calculated position is
RA, Dec = 0.2037, +44.5739 deg which is
   RA(J2000)  =  00h 00m 48.9s     Dec(J2000) = +44d 34' 26.0"
with an uncertainty of 3.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 85%.

The mask-tagged light curve shows that the GRB entered the BAT field of view at
~T-80 sec during a pre-planned slew.  The flux slowly declined after this point
and then increased at about T+600 seconds.  There were less significant
fluctuations until the end of the event data at about T+1300.  T90 (15-350 keV)
is  1088.0 +- 20.0 sec (estimated error including systematics).

The time-averaged spectrum from T+0 to T+963 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.82 +- 0.32.  The fluence in the 15-150 keV band is 1.9 +- 0.4 x 10-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.00 sec in the 15-150 keV band
is 0.0 +- 0.0 ph/cm2/sec.  All the quoted errors are at the 90% confidence

The results of the batgrbproduct analysis are available at
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