GCN Circular 13503
Subject
GRB 120722A: Swift-BAT refined analysis
Date
2012-07-22T22:40:29Z (12 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), A. Melandri (INAF-OAB), D. M. Palmer (LANL),
M. Stamatikos (OSU), 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 recent telemetry downlinks,
we report further analysis of BAT GRB 120722A (trigger #528195)
(Melandri, et al., GCN Circ. 13499). The BAT ground-calculated position is
RA, Dec = 230.489, 13.249 deg, which is
RA(J2000) = 15h 21m 57.4s
Dec(J2000) = +13d 14' 56.8"
with an uncertainty of 3.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 19%.
The mask-weighted light curve shows a couple overlapping peaks starting
at ~T-10 sec, peaking at ~T+23 sec, and ending at ~T+50 sec.
T90 (15-350 keV) is 42.4 +- 10.5 sec (estimated error including systematics).
The time-averaged spectrum from T-0.3 to T+47.5 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.90 +- 0.25. The fluence in the 15-150 keV band is 1.2 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+24.02 sec in the 15-150 keV band
is 1.0 +- 0.3 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/528195/BA/