SIMBAD references

We have extended the work of Papers I and II of this series to determine at a higher spatial resolution the properties of the embedded Orion-S Molecular Cloud that lies within the ionized cavity of the Orion Nebula and of the thin ionized layer that lies between the Cloud and the observer. This was done using existing and new [N II] (658.3 nm) and [O III] (500.7 nm) spectra that map the central region of the Orion Nebula (the Huygens region). Although our observations show that the surface brightness of the ionized layer on the Orion-S Molecular Cloud and that of the nearer foreground ionized layer are linked, the process by which this is done is unclear. It is shown that the Cloud modifies the outer parts of the Huygens region in the direction of the extended hot X-ray gas.