GCN Circular 4586
Subject
GRB 060124: Extremely long burst, Swift-BAT refined analysis
Date
2006-01-25T01:02:04Z (18 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <jayc@milkyway.gsfc.nasa.gov>
E. Fenimore (LANL), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/NRC), N. Gehrels (GSFC), D. Hullinger (GSFC/UMD),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), T. McMahon (Langston U.),
D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/NRC),
G. Sato (ISAS), J. Tueller (GSFC), N. White (GSFC)
on behalf of the Swift-BAT team:
Using the data set from T-50.0 to T+1000.0 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 060124 (trigger #178750)
(Holland, et al., GCN 4570). The BAT ground-calculated position is
(RA,Dec) = 77.128, 69.724 deg {5h 8m 30.6s, 69d 43' 27.9"} (J2000)
+- 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding
was 62%.
The BAT mask-weighted lightcurve has a precursor from T-3 to T+13 sec,
then three major peaks: T+520 to T+550 sec, T+560 to T+580 sec (with the
largest flux), and T+690 to T+710 sec. Thus the total duration is one of
the longest recorded by BATSE or Swift.
The spectrum of the main peaks appears slightly harder than the precursor,
but so far we have detailed data for the precursor only. The spectrum of
the precursor from T-1.2 to T+13.2 is best fit by a simple power-law model
with a photon index of 1.89 +- 0.19. The fluence of the precursor emission
in the 15-150 keV band is (4.6 +- 0.5) x 10^-07 erg/cm2. The peak flux in
the 15-150 keV band was about 4.5 +- 0.5 counts/cm2/sec at T+570.
We have made a preliminary estimate of the total fluence in the BAT
energy range for this burst by scaling the fluence of the precursor
by the mask-weighted counts ratio between the entire burst and the
precursor. This estimated total fluence is ~7 x 10^-6 erg/cm2 in the
15-150 keV band.