GCN Circular 11902
Subject
GRB 110407A: Swift-BAT refined analysis
Date
2011-04-07T23:10:05Z (14 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
T. N. Ukwatta (MSU), 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), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), C. W. Wolf (PSU)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+800 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110407A (trigger #450884)
(Wolf, et al., GCN Circ. 11894). The BAT ground-calculated position is
RA, Dec = 186.022, 15.726 deg, which is
RA(J2000) = 12h 24m 05.3s
Dec(J2000) = +15d 43' 33.2"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 77%.
The mask-weighted light curve shows several overlapping peaks starting
at ~T-10 sec, peaking at ~T+15 sec, and ending around T+275 sec.
T90 (15-350 keV) is 145 +- 15 sec (estimated error including systematics).
The time-averaged spectrum from T-2.9 to T+158.8 sec is best fit by a power law
with an exponential cutoff. This fit gives a photon index 0.73 +- 0.64,
and Epeak of 57.9 +- 15.1 keV (chi squared 46.5 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 1.7 +- 0.2 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+27.64 sec in the 15-150 keV band is
0.5 +- 0.1 ph/cm2/sec. A fit to a simple power law gives a photon index
of 1.73 +- 0.12 (chi squared 55.6 for 57 d.o.f.). 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/450884/BA/