M. Stamatikos (OSU), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
A. D'Ai (INAF-IASFPA), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. Malesani (DARK/NBI),
D. M. Palmer (LANL), T. Sakamoto (AGU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of the recent outburst from SGR 1617-5103,
a.k.a. 1E 161348-5055 and 2E 1613.5-5053 (trigger #700791; D'Ai et al.,
GCN Circ. 19547, formerly identified as a GRB). The BAT ground-calculated
RA, Dec = 244.357, -51.060 deg which is
RA(J2000) = 16h 17m 25.7s
Dec(J2000) = -51d 03' 37.0"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 71%.
The mask-weighted light curve shows a very short spike that starts and peaks
at ~T0, and ends at ~T+0.008 s. T90 (15-350 keV) is 0.008 +- 0.004 sec (estimated
error including systematics).
We note that the short single spike seen by BAT is typical of SGR large flares.
This could be an SGR flare from the central neutron star of SNR RCW103.
The time-averaged spectrum from T+0.0 to T+0.008 sec is best fit by a simple
power-law model (chi2 = 37.71; 57 degrees of freedom). The power law index of the
time-averaged spectrum is 1.77 +- 0.26. The fluence in the 15-150 keV band
is 1.9 +- 0.4 x 10^-8 erg/cm2. If using a black-body model, which is more suitable
for an SGR, the spectral fit finds that kT = 9.9 +- 1.9 keV (chi2 = 48.25; 57 degrees
of freedom). All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at