GCN Circular 8275
Subject
GRB 080919, Swift-BAT refined analysis
Date
2008-09-19T15:06:18Z (16 years ago)
From
Hans Krimm at NASA-GSFC <hans.a.krimm@nasa.gov>
W.H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC),
J.R. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H.A. Krimm (GSFC/USRA), C.B. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),
D.M. Palmer (LANL), A.M. Parsons (GSFC), B. Preger (ASDC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T.N. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 080919 (trigger #325268)
(Preger, et al., GCN Circ. 8270). The BAT ground-calculated position is
RA, Dec = 265.221, -42.375 deg which is
RA(J2000) = 17h 40m 53.0s
Dec(J2000) = -42d 22' 29.5"
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 99%.
The mask-weighted light curve shows a broad peak of approximately 750 msec
duration starting at T+0 followed immediately by a weaker ~400 msec
peak seen mostly below 50 keV. T90 (15-350 keV) is 0.6 +- 0.1 sec
(estimated error including systematics).
The time-averaged spectrum from T+0.1 to T+0.8 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum
is 1.10 +- 0.26. The fluence in the 15-150 keV band is 7.2 +- 1.1 x 10-8 erg/cm2.
The 1-sec peak photon flux measured from T-0.08 sec in the 15-150 keV band
is 1.2 +- 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/325268/BA/