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GCN Circular 11945

Subject

GRB 110420A: Swift-BAT refined analysis

Date

2011-04-20T23:59:45Z (13 years ago)

From

Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>

GRB 110420A: Swift-BAT refined analysis
 
H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), V. Mangano (INAF-IASFPA),
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-61 to T+242 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110420A (trigger #451757)
(Mangano, et al., GCN Circ. 11941Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 2.164, -37.877 deg which is 
   RA(J2000)  =  00h 08m 39.3s 
   Dec(J2000) = -37d 52' 35.5" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 15%.
 
The mask-weighted light curve shows a single peak with some structure
starting at ~T-15 sec, peaking at ~T+8 sec, and ending at ~T+35 sec.
T90 (15-350 keV) is 11.8 +- 0.9 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.1 to T+16.0 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.30 +- 0.07.  The fluence in the 15-150 keV band is 5.9 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+8.04 sec in the 15-150 keV band
is 14.0 +- 0.9 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/451757/BA/