GCN Circular 8250
Subject
GRB 080916B, Swift-BAT refined analysis
Date
2008-09-16T20:55:15Z (16 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC), J. Cummings (GSFC/UMBC),
E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), G. Stratta (ASDC),
J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team) report:
Using the data set from T-239 to T+617 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 080916B (trigger #324907)
(Strata, et al., GCN Circ. 8240). The BAT ground-calculated position is
RA, Dec = 163.632, 69.061 deg, which is
RA(J2000) = 10h 54m 31.6s
Dec(J2000) = +69d 03' 38.2"
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 53%.
The mask-weighted light curve shows a weak FRED-like peak starting
at ~T-4 sec, peaking at ~T+3 sec, and ending at ~T+50 sec. There is a
possibility of very weak emission lasting out to at least T+350 sec,
at which time the spacecraft slewed away fro the burst location.
T90 (15-350 keV) is 32 +- 8 sec (estimated error including systematics).
The time-averaged spectrum from T-3.3 to T+35.7 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.49 +- 0.23. The fluence in the 15-150 keV band is 6.3 +- 0.9 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+3.30 sec in the 15-150 keV band
is 0.6 +- 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/324907/BA/