The cas a-like SNR 1E 0102.2-7219 in the Small Magellanic Cloud: An asymmetric bipolar explosion

We have used the Wide Field Spectrograph on the 2.3 m telescope at Siding Spring Observatory to map the [O III] λ5007 dynamics of the young oxygen-rich supernova remnant 1E 0102.2-7219 in the Small Magellanic Cloud. From the resultant data cube, we have been able to reconstruct the full three-dimensional structure of the system of [O III] filaments. From this we are able to deduce that the ejecta trace an asymmetric bipolar structure. The redshifted gas contains fainter clumps but with higher velocities than the blueshifted gas. The major axis of the explosion is inclined at ∼40° to the line of sight. This structure shows that the supernova explosion has been influenced both by the rotation of the progenitor star and, presumably, by a global rotational instability following core collapse.