[vsnet-grb-info 15241] GRB 140705A / SGR 1935+2154: Probable association with supernova remnant G57.2+0.8

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16533
SUBJECT: GRB 140705A / SGR 1935+2154: Probable association with supernova remnant G57.2+0.8
DATE:    14/07/07 08:19:25 GMT
FROM:    Bryan Gaensler at U of Sydney  <bmg at physics.usyd.edu.au>

B. M. Gaensler (U. Sydney / CAASTRO) reports:

I note that the newly identified magnetar SGR 1935+2154 (GCN 16522; ATel 6294) is coincident with the Galactic supernova remnant (SNR) G57.2+0.8 (Sun et al., 2011, A&A, 536, A83, and references therein).

Specifically, the location of the SGR as determined by Swift XRT (ATel 6294) sits very close to the geometric centre of the SNR. A 1.4 GHz radio image of the SNR taken from the VLA Galactic Plane Survey (Stil et al., 2006, AJ, 132, 1158), and showing the position of the SGR, is available at:

http://www.physics.usyd.edu.au/~bmg/fig_sgr1935+2154_snr.png

This is a relatively uncrowded region of the Galactic plane, implying a high probability of a physical association between SGR 1935+2154 and SNR G57.2+0.8. The SGR's location at the centre of a SNR is similar to that previously found for other SGRs such as 1E 2259+586 in CTB 109, 1E 1841-045 in Kes 73 and 1E 1547.0-5408 in G327.2-0.1.

No reliable age or distance estimate is available for SNR G57.2+0.8.