Deciphering the 3-D Orion Nebula-III: Structure on the NE boundary of the Orion-S Embedded Molecular Cloud

TL;DR

This study uses high-resolution spectral data to analyze the structure of the Orion-S Molecular Cloud within the Orion Nebula, revealing how the cloud influences the nebula's ionized regions and their brightness.

Contribution

It provides new high-resolution spectral analysis of the Orion-S Cloud and clarifies the relationship between ionized layers and the cloud's impact on the nebula's structure.

Findings

The Orion-S Cloud modifies the outer parts of the Huygens Region.

The ionized layer's surface brightness is linked to a foreground Nearer Ionized Layer.

The cloud's influence extends to the hot X-ray emitting gas.

Abstract

We have extended the work of Papers I and II of this series to determine at 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 [NII](658.3 nm) and [OIII] (500.7 nm) spectra that map the central region of the Orion Nebula (the Huygens Region). However, it remains unclear how the surface brightness of the ionized layer on the Orion-S Molecular Cloud and that of a foreground Nearer Ionized Layer are linked, as the observations show they must be. It is shown that the Cloud modifies the outer parts of the Huygens Region in the direction of the extended hot X-ray gas.