GCN Circular 5011
Subject
GRB 060427: Refined analysis of the Swift-BAT burst
Date
2006-04-27T21:21:57Z (18 years ago)
From
Scott Barthelmy at NASA/GSFC <Scott@lheamail.gsfc.nasa.gov>
H. Krimm (GSFC/USRA), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hullinger (BYU-Idaho), V. Mangano (INAF-IASFPA), C. Markwardt (GSFC/UMD),
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 data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 060427 (trigger #207281)
(Mangano, et al., GCN 5006). The BAT ground-calculated position is RA,Dec =
124.175,+62.654 deg {8h 16m 42.0s,+62d 39' 13.4"} (J2000) +- 2.1 arcmin,
(radius, sys+stat, 90% containment). The partial coding was 71%.
The mask-weighted lightcurve shows a broad peak starting at ~T-20 sec
and lasting to ~T+80 sec. T90 (15-350 keV) is 64 +- 5 sec
(estimated error including systematics).
The time-averaged spectrum from T-10.0 to T+60.0 is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.87 +- 0.29. The fluence in the 15-150 keV band is
5.0 +- 0.9 x 10^-07 erg/cm2. The 1-sec peak photon flux measured
from T+5.00 sec in the 15-150 keV band is 0.3 +- 0.1 ph/cm2/sec.
All the quoted errors are at the 90% confidence level.