GCN Circular 4435
Subject
GRB 060105: BAT refined analysis
Date
2006-01-05T20:45:09Z (18 years ago)
From
Hans Krimm at NASA-GSFC <krimm@milkyway.gsfc.nasa.gov>
C. Markwardt (GSFC/UMD), L. Angelini (GSFC/JHU), L. Barbier (GSFC),
S. Barthelmy (GSFC), J. Cummings (GSFC/ORAU), E. Fenimore (LANL),
N. Gehrels (GSFC), J. Greiner (MPE), D. Hullinger (UMD),
H. Krimm (GSFC/USRA), 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-120 to T+300 sec from the recent
telemetry downlink, we report further analysis of BAT GRB 060105
(trigger #175942) (Ziaeepour, et al., GCN 4429). The BAT ground-
calculated position is
(RA,Dec) = 297.488, 46.359 {19h 49m 57.1s, 46d 21' 32.4"} [deg; J2000]
+- 0.9 arcmin, (radius, sys+stat, 90% containment). This is 36 arcsec
from the BAT onboard position and 52 arcsec from the Swift XRT onboard
position (Ziaeepour et al, GCN #4429). The partial coding was 28.5%.
The BAT mask-weighted light curve has 3 main peaks, each with multiple
sub-peaks, an overall flat-topped shape, and similar spectra. The
first is T-22 to T-15 sec, the second from T-3 to T+11 sec, and the
third from T+23 to T+36 sec. There is softer, weaker emission in the
15-50 keV band out to at least T+150. T90 (15-350 keV) is (55 +- 5)
sec (estimated error including systematics).
The power law index of the time-averaged spectrum is 1.11 +- 0.03.
The fluence in the 15-150 keV band is (1.82 +- 0.04) x 10^-05 erg/cm2.
The 1-sec peak photon flux measured from T+30.42 sec in the 15-150 keV
band is (7.5 +- 0.4) ph/cm2/sec. All the quoted errors are at the 90%
confidence level. This GRB is among the brightest bursts seen by BAT.