GCN Circular 8862
Subject
GRB 090129: Swift-BAT refined analysis
Date
2009-01-30T13:58:35Z (15 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
T. N. Ukwatta (GWU), H. Ziaeepour (UCL-MSSL)
(i.e. the Swift-BAT team):
Using the data set from T-120 to T+962 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 090129 (trigger #341504)
(Ziaeepour, et al., GCN Circ. 8861). The BAT ground-calculated position is
RA, Dec = 269.105, -32.793 deg which is
RA(J2000) = 17h 56m 25.1s
Dec(J2000) = -32d 47' 34.8"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 89%.
The mask-weighted light curve shows emission starting at ~T-30 sec,
then a large-amplitude FRED peak that returns to background at ~T+70 sec.
T90 (15-350 keV) is 17.5 +- 2.7 sec (estimated error including systematics).
The time-averaged spectrum from T-0.2 to T+27.0 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.88 +- 0.06. The fluence in the 15-150 keV band is 2.1 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.00 sec in the 15-150 keV band
is 3.7 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/341504/BA/