The 4 to 8 micron spectrum of the galactic center

Observations of the complex Sgr A W(N) with a 28-arcsec beam and 1.5% spectral resolution are reported. Neither unidentified absorption features at 6.0 and 6.8 microns nor emission features at 6.2 and 7.7 microns were detected. The absence of the absorption features demonstrates that they are not characteristic of general interstellar extinction. The absence of emission features suggests that there is considerable distance between the ionized gas and the molecular clouds. The absence of 6.2- and 7.7-micron emission features also suggests that a feature previously seen at 3.3-3.4 microns is an absorption at 3.4 microns, and this absorption is apparently characteristic of interstellar extinction. The strength of the forbidden Ar II emission indicates an overabundance of argon. CO absorption seen at 4.67 microns indicates that saturation effects are not large, and there is evidently a large velocity dispersion in the line of sight to the infrared sources.