Difference Image of the HH 47 Jet
An H-alpha minus [S II] difference image of the HH 47 jet based on HST images.
[S II]-strong regions are black, and H-alpha-strong regions are white. The
wisps and filaments seen in the H-alpha image are located at the edges of
the [S II]-bright jet where it shows abrupt changes in direction.
Field stars do not subtract out, because the [S II] filter is much wider
than the H-alpha filter. The reflection nebula has almost
disappeared because by chance the presence of
H-alpha emission from the embedded T Tauri star compensates for
the wider bandwidth of the [S II] filter.