TITLE:   GCN CIRCULAR
NUMBER:  11367
SUBJECT: GRB 101023A: Swift-BAT refined analysis
DATE:    10/10/24 03:20:47 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
C. J. Saxton (UCL-MSSL), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+542 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 101023A (trigger #436981)
(Saxton, et al., GCN Circ. 11363).  The BAT ground-calculated position is
RA, Dec = 317.949, -65.389 deg, which is 
   RA(J2000)  =  21h 11m 47.8s 
   Dec(J2000) = -65d 23' 20.1" 
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 11%.
 
The mask-weighted light curve shows a small peak starting at ~T-10 sec, peaking
at T_zero.  The main emission starts with about 3 overaping peaks peaking at
~T+54 and ~T+58 sec and ending at ~T+140 sec.  T90 (15-350 keV) is 80.8 +- 2.2 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-11.0 to T+137.3 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.26 +- 0.15, 
and Epeak of 101.1 +- 18.9 keV (chi squared 45.1 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 2.7 +- 0.1 x 10^-5 erg/cm2
and the 1-sec peak flux measured from T+57.34 sec in the 15-150 keV band is
0.0 +- 0.0 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.67 +- 0.03 (chi squared 69.3 for 57 d.o.f.).  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/436981/BA/