GCN Circular 14099
Subject
Swift-BAT refined analysis of SGR 1E 1841-045 (Trigger=543763)
Date
2012-12-24T19:38:58Z (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 (AGU),
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-119 to T+183 sec from recent telemetry downlinks,
we report further analysis of BAT trigger #543763 on SGR 1E 1841-045
(Barthelmy, et al., GCN Circ. 14098). The BAT ground-calculated position is
RA, Dec = 280.303, -4.916 deg, which is
RA(J2000) = 18h 41m 12.8s
Dec(J2000) = -04d 54' 58.0"
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 35%.
The mask-weighted light curve shows a single spike where
T90 (15-350 keV) is 0.012 +- 0.009 sec (estimated error including systematics).
Several models are fit over the time-averaged spectrum from T+0.000 to T+0.016 sec.
A simple power-law model yields a poor fit with the power law index of 2.60 +- 0.32
(chi squared 55.89 for 57 d.o.f.). The fluence in the 15-150 keV band is 1.2 +- 0.3 x 10^-8 erg/cm2.
The cutoff power-law model yields a fit with E_peak = 40.6 +- 4.6 keV,
power law indix = 3.6 +- 3.8, and chi squared 32.18 using 59 d.o.f.
A single blackbody fit to the time-averaged spectrum shows the blackbody
temperature of 9.8 +- 1.0 keV (chi squared 34.05 for 59 d.o.f.).
A thermal bremsstrahlung model fit shows the temperature of 34.36 +- 9.34 keV
(chi squared 46.93 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/543763/BA/
We note the previous activity of this source: Swift BAT triggers 526660 15 Jul 2012
(GCN 13475 & 13480), 456505 on 02 Jul 2011 (GCN 12103 & 12104), 455904 on 23 Jun 2011
(GCN 12079 & 12082), and 445776 on 11 Feb 2011 (GCN 11673).