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GCN Circular 11764

Subject

GRB 110223A: Swift-BAT refined analysis

Date

2011-02-24T13:27:17Z (14 years ago)

From

Michael Stamatikos at OSU/GSFC <michael.stamatikos-1@nasa.gov>

W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), 
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt 
(GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos 
(OSU/NASA/GSFC), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+300 sec from the recent telemetry downlink, 
we report further analysis of BAT GRB 110223A (trigger #446674) 
(Sakamoto, et al., GCN Circ. 11753Loading...
 
 ).  The BAT ground-calculated position is 
RA, Dec = 345.386, 87.586 deg which is 
   RA(J2000)  =  23h 01m 32.7s 
   Dec(J2000) = +87d 35' 11.3" 
with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 60%.
 
The mask-weighted light curve shows a FRED-like peak at ~T+0.5 sec. T90 (15-350 keV) 
is 7.0 +- 2.2 sec (estimated error including systematics).
 
The time-averaged spectrum from T+0.1 to T+8.1 sec is best fit by a simple 
power-law model.  The power law index of the time-averaged spectrum is 
1.70 +- 0.33.  The fluence in the 15-150 keV band is 1.6 +- 0.4 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T+0.08 sec in the 15-150 keV band is 
0.6 +- 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/446674/BA/