GCN Circular 3840
Subject
SUBJECT: GRB050820B: Refined analysis of the Swift-BAT burst
Date
2005-08-21T02:33:16Z (19 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori@milkyway.gsfc.nasa.gov>
E. Fenimore (LANL), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/NRC), N. Gehrels (GSFC), D. Hullinger (GSFC/UMD),
K. Hurley (Berkeley), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
J. Norris (GSFC), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/NRC), G. Sato (ISAS), J. Tueller (GSFC)
on behalf of the Swift-BAT team:
Using the full data set from the recent telemetry downlink, we report
further analysis of Swift-BAT GRB 050820B (trigger #151334)
(Page, et al., GCN 3839). The ground-analysis position is
RA,Dec 135.594,-72.639 (J2000) with an uncertainty of 2 arcmin
(radius, 90%, stat+sys).
The light curve show a peak at T+1 sec and a cluster of merged
peaks at T+8 sec. T90 is 13 +/-2 sec.
Fitting a cutoff power law over the interval from T+0.2 to T+17.3 sec,
the photon index is 0.5 +/- 0.2 and Epeak is 100 (-10/+15) keV
with a fluence of 2.8 +/- 0.2 x 10^-6 erg/cm^2 in the 15-350 keV
band (90% c.l.). The peak flux in a 1-sec wide window starting at
T+8.7 seconds is 4.7 +/- 0.3 ph/cm^2/sec (15-350 keV).