GCN Circular 9672
Subject
GRB 090715B: Swift-BAT refined analysis
Date
2009-07-16T03:12:09Z (15 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU), L. Vetere (PSU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 090715B (trigger #357512)
(Vetere, et al., GCN Circ. 9668). The BAT ground-calculated position is
RA, Dec = 251.337, 44.837 deg, which is
RA(J2000) = 16h 45m 20.9s
Dec(J2000) = +44d 50' 12.6"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
The mask-weighted light curve shows a series of peaks. The first starts
at ~T-10 sec, peaks at ~T+7 sec, and returns almost to background at T+35 sec.
The second peak start at ~T+45 sec and ends at ~T+100 sec. The third peak
starts at ~T+230 sec and ends at ~T+290 sec.
T90 (15-350 keV) is 266 +- 11 sec (estimated error including systematics).
The time-averaged spectrum from T-11.6 to T+292.3 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.57 +- 0.07. The fluence in the 15-150 keV band is 5.7 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+6.46 sec in the 15-150 keV band
is 3.8 +- 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/357512/BA/