Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 9494

GRB 090607: Swift-BAT refined analysis of the SHB
2009-06-07T11:32:02Z (15 years ago)
Scott Barthelmy at NASA/GSFC <>
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), F. E. Marshall (NASA/GSFC) D. M. Palmer (LANL),
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-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 090607 (trigger #354299)
(Marshall, et al., GCN Circ. 9491).  The BAT ground-calculated position is
RA, Dec = 191.194, 44.108 deg, which is 
   RA(J2000)  =  12h 44m 46.7s 
   Dec(J2000) = +44d 06' 28.4" 
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 96%.
The mask-weighted light curve shows two narrow peaks.  The first starts
at T-0.1 sec, peaks at T+0.1 sec, and ends at T+0.7sec.  The second peak
starts at ~T+1.7 sec, peaks at T+2.2 sec, and ends at T+2.5 sec.  There is
no hint of emission out to at least T+243 sec.  T90 (15-350 keV) is
2.3 +- 0.1 sec (estimated error including systematics).
The time-averaged spectrum from T+0.1 to T+2.5 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.25 +- 0.30.  The fluence in the 15-150 keV band is 1.1 +- 0.2 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-0.01 sec in the 15-150 keV band
is 0.7 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence

Based on the shortness of the duration and the spectral hardness, we believe
this to be a short hard burst.
The results of the batgrbproduct analysis are available at
Looking for U.S. government information and services? Visit