The Central Molecular Zone (CMZ) is the approximately 250 pc radius region at the center of our Galaxy. It contains a black hole, a large stellar bar, massive stellar clusters, and a number of the densest molecular clouds in the Galaxy (most forming stars but some not) on a variety of orbits. Our detailed understanding of structures within the CMZ is possible because of its proximity, and it is therefore a model for all normal galactic nuclei, near and far. Here we report observations of far-infrared fine structure lines with SOFIA/FIFI-LS, Herschel/PACS, and SOFIA-upGREAT that clarify the physical structure of the Galactic Center Arches and Sickle regions, which lie deep within the CMZ's most energetic zone, some 5 to 10 pc from the central black hole. This allows us to probe the roles that hot stellar clusters, distributed B-type stars, and interactions between magnetic fields and molecular clouds play in producing the radiation field across the inner 10 pc of the Galactic Center.
SOFIA and Herschel Observations of Far-Infrared Fine Structure Lines from Deep Within the Galactic Center