TITLE:   GCN CIRCULAR
NUMBER:  11475
SUBJECT: GRB 101219B: Swift-BAT refined analysis
DATE:    10/12/19 21:59:06 GMT
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), J. M. Gelbord (PSU), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+766 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 101219B (trigger #440635)
(Gelbord, et al., GCN Circ. 11473).  The BAT ground-calculated position is
RA, Dec = 12.259, -34.556 deg which is 
   RA(J2000)  =  00h 49m 01.9s 
   Dec(J2000) = -34d 33' 21.6" 
with an uncertainty of 3.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 7%.
 
The mask-weighted light curve shows a broad peak starting at ~T+20 sec
and ending at ~T+60 sec.  However, given that there was a pre-planned slew
ending just before T_zero, we can not rule out that was actvitity before
this source came into the BAT FoV.  T90 (15-350 keV) is 34 +- 5 sec
(estimated error including systematics).
 
The time-averaged spectrum from T+10 to T+60 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.56 +- 0.16.  The fluence in the 15-150 keV band is 2.1 +- 0.4 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+26.84 sec in the 15-150 keV band
is 0.6 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.