GCN Circular 13052
Subject
GRB 120312A: Swift-BAT refined analysis
Date
2012-03-12T22:24:54Z (12 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
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), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+736 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 120312A (trigger #517566)
(Stamatikos, et al., GCN Circ. 13049). The BAT ground-calculated position is
RA, Dec = 251.812, 23.881 deg, which is
RA(J2000) = 16h 47m 14.8s
Dec(J2000) = +23d 52' 50.3"
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 35%.
The mask-weighted light curve shows a single slightly symmetric peak
starting at ~T-10 sec, peaking at ~T+0.5 sec, and ending at ~T+35 sec.
T90 (15-350 keV) is 14.2 +- 3.4 sec (estimated error including systematics).
The time-averaged spectrum from T-1.42 to T+15.87 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.72 +- 0.23. The fluence in the 15-150 keV band is 5.7 +- 0.8 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.95 sec in the 15-150 keV band
is 1.3 +- 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/517566/BA/