GCN Circular 2973
Subject
GRB050124: Refined BAT position, spectral and fluence information
Date
2005-01-24T17:57:48Z (19 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <jayc@milkyway.gsfc.nasa.gov>
J. Cummings (GSFC), S. Barthelmy, L. Barbier (GSFC), A. Breeveld (MSSL),
J. Cannizzo (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hullinger (GSFC/UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
K. McLean (LANL), T. McMahon (Langston U.), D. Palmer (LANL),
A. Parsons (GSFC), G. Sato (ISAS), P. Schady (MSSL), T. Sakamoto (GSFC),
A. Smale (NASA HQ), M. Suzuki (Saitama), J. Tueller (GSFC)
This is a followup report on Swift/BAT GRB050124 (GCN Circ. 2972, Markwardt
et al.) The ground-calculated BAT location is RA, Dec 192.884, 13.024 degrees
(J2000). At 43 degrees from the BAT boresight, we expect the uncertainty
to be primarily systematic due to currently uncalibrated image distortion
(Swift/BAT image calibration activities are still in progress). The
systematic uncertainty is approximately 3 arcmin (radius).
Further analysis yields a fluence of (2.1 +- 0.2) x 10^-6 ergs/cm2 and a
1-second peak flux of (6.8 +- 0.4) ph/cm2/s in the 15-350 keV band. The
power-law photon index is 1.48 in the 20 - 150 keV band.
T90 is 4.1 seconds and T50 is 2.1 seconds. The burst had 2 peaks, the first
2 seconds long with a rise in 0.1 seconds from a baseline that was slightly
elevated for about 1.4 seconds, and the second about 1 second long. There is
a low-significance (3.6 sigma image) hint of a 1-second precursor at -16
seconds from the trigger.