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GCN Circular 14343

Subject

GRB 130327A: Swift-BAT refined analysis

Date

2013-03-27T21:54:49Z (12 years ago)

From

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

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),
A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
A. M. Parsons (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-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 130327A (trigger #552063)
(Ukwatta, et al., GCN Circ. 14140Loading...
 
 ).  The BAT ground-calculated position is
RA, Dec = 91.984, 55.732 deg, which is 
   RA(J2000)  =  06h 07m 56.2s 
   Dec(J2000) = +55d 43' 56.2" 
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 61%.
 
The mask-weighted lightcurve shows a single peak starting at ~T-5 sec,
peaking at ~T+1 sec, and ending at ~T+8 sec.  T90 (15-350 keV) is
9.0 +- 2.8 sec (estimated error including systematics).
 
The time-averaged spectrum from T-4.38 to T+5.62 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.26 +- 0.36.  The fluence in the 15-150 keV band is 2.3 +- 0.5 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.62 sec in the 15-150 keV band
is 0.9 +- 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/552063/BA/