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GCN Circular 3316

Subject
GRB 050422: Swift-BAT refined analysis
Date
2005-04-22T15:31:54Z (20 years ago)
From
Louis M Barbier at NASA/GSFC/Swift <lmb@cosmicra.gsfc.nasa.gov>
M. Suzuki (Saitama), L. Barbier (GSFC), S. Barthelmy (GSFC), 
J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC), 
D. Hullinger (UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/NRC), 
G. Sato (ISAS), J. Tueller (GSFC), J. Cannizzo (GSFC/UMBC),
M. Ajello (MPE), M. Chester (PSU)  on behalf of the Swift/BAT team:

At 07:52:39 UT Swift-BAT detected GRB 050422 (trigger= 115214)
(GCN Circ 3314, Barbier et al.).  The refined BAT ground position
is (RA,Dec) = 324.454, 55.798, [deg; J2000] +- 3 arcmin, (95%
containment).  The partial coding was 98%.  

The light curve shows multiple peaks, with the main peak 
starting about T+42 seconds after the trigger and with another
hard peak at T+102 seconds.  T90 (15-350 keV) is (59.2 +- 0.3) 
seconds (estimated error including systematics).  

The photon index of the time-averaged spectrum is 1.4 +- 0.2.  
The fluence in the 15-350 keV band is (1.2 +- 0.2) x 10^-6 erg/cm2.  
The 1-s peak photon flux measured from T0+53.1 seconds in the 15-350 
band is (0.7 +- 0.1 ) ph/cm2/s.  All the quoted errors are at the 90% 
confidence level.
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