GCN Circular 7778
Subject
Konus-Wind observation of reactivation of SGR 1627-41
Date
2008-05-29T09:40:04Z (16 years ago)
From
Valentin Pal'shin at Ioffe Inst <val@mail.ioffe.ru>
S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P.
Oleynik, M. Ulanov and T. Cline, on behalf of the Konus-Wind team report:
On May 28, SGR 1627-41 has resumed its activity (Palmer et al.
GCN 7777, ATel #1548). Konus-Wind observed in the waiting mode a number
of SGR-like bursts (short and soft) on this day.
The most intense burst triggered Konus-Wind at T0=38088.659 s UT
(10:34:48.659). The burst lc shows a single pulse with a duration of
~270 ms.
As observed by Konus-Wind the burst had a fluence of
(1.60 +/- 0.10)x10^-6 erg/cm2, and a 2-ms peak flux
measured from T0-0.004 s of (3.94 +/- 0.60)x10^-5 erg/cm2
(both in the 20-200 keV range).
The spectrum of the burst (from T0 to T0+0.128 s) is well fitted
(in the 20-200 keV range) by the OTTB spectral model:
dN/dE ~ E^{-1} exp(-E/kT)
with kT = 19.9(-1.5, +1.6) keV (chi2 = 11.9/12 dof).
The burst demonstrates a significant spectral evolution which is typical
for SGR 1627-41 (see the Konus catalog of SGR activity (Aptekar et al.
2001, ApJSS, 137, 227): http://www.ioffe.rssi.ru/LEA/SGR/Catalog/).
The Konus-Wind light curve of this burst is available
at http://www.ioffe.rssi.ru/LEA/SGRs/080528_T38088/
The following is a list of the most intense bursts observed in the
waiting mode on May 28. The source of these short soft bursts is in the
south ecliptic latitude, so likely all of them originated from SGR
1627-41 (most of them were detected and localized by the Swift-BAT).
--------------------------------------------------------------------
Time Fluence 20-200 keV
-------------------------------------------------------------------
08:21:50 1.6E-7
09:53:06 2.8E-7
10:02:49 2.4E-7
10:12:23 1.2E-7
10:14:27 2.2E-7
10:15:31 2.4E-7
10:19:21 1.8E-7
10:19:33 3.0E-7
10:19:39 2.1E-7
10:19:47 7.7E-7
10:20:32 1.0E-6
18:26:47 2.3E-7
------------------------------------------------------------------
The last burst from SGR 1627-41 to trigger Konus-Wind
was on July 12, 1998
(http://www.ioffe.rssi.ru/LEA/SGR/Catalog/Data/1627/980712.htm).