Side shocks in HH 47

A detailed view of the region around knot A_{16} located at a pronounced bend in the jet: (a) H-alpha; (b) [S II]; (c) H-alpha+[S II]; (d) a cartoon showing the possible locations of the shock front and the flow of the gas in the fast core of the jet. The regions marked 'FAST' and 'SLOW' were determined from radial velocity measurements of the emission lines.