GCN Circular 116
Subject
SGR1627-41, RXTE/ASM observations
Date
1998-06-19T17:20:20Z (27 years ago)
From
Don Smith at MIT <dasmith@space.mit.edu>
D. A. Smith and A. M. Levine, on behalf of the RXTE/ASM teams at
MIT and NASA/GSFC, report:
"Although the ASM did not observe any of the BATSE-detected events from
SGR 1627-41, during the interval from Jun 15 to Jun 19, three short
(<~1 s) burst events were detected in SSC 3 at May 17.943917,
17.954243, and 18.010803 (UTC).
During the first event, the original BATSE location (GCN 107) was
outside the FOV of the ASM. The full width of the FOV of SSC 3 during
the first event restricts the range of declination values along the
IPN annulus (GCN 115) between -44.4 and -56.4 degrees. This is fully
consistent with the revised BATSE position reported in GCN 113.
Due to low signal-to-noise, our standard cross-correlation technique
was unable to isolate these events in our position data, but given the
IPN annulus, we were able to search along it for a best-fit location.
We find a minimum reduced chi-squared at R.A. = 16h35m50s, Decl.=
-47o32' for event 1 and R.A. = 16h35m50s, Decl.= -47o39' for event 2
(1-sigma error of 4' in Decl. in both cases). Both positions are
consistent with the location of the SNR (g337.0-0.1) mentioned in
GCN 113.
If we assume these bursts are coming from SNR G337.0-0.1, we can use
its location to measure the burst fluxes:
Event Fluence Peak Flux (2-12 keV)
(10^{-7} erg/cm^2) (10^{-7} erg/cm^2/s)
1.5-3 3-5 5-12 kev (1-s averages)
1 <0.6 <0.4 2.1 (+- 0.3) 1.1
2 <0.8 <0.4 2.9 (+- 0.5) 2.8
Upper limits are 2-sigma. We do not yet have pointing information for
the observation of the third burst."