VELOCITY-RESOLVED INFRARED RECOMBINATION-LINE SPECTROSCOPY OF NGC-253

Observations at high spectral resolution of the Br gamma hydrogen reco mbination line are presented for the central 25 arcsec of the starburs t galaxy NGC 253. The rotation curve derived from these data shows sol id body rotation consistent with recent interferometric CO measurement s but not with rotation curves derived from optical emission lines. Th is discrepancy is most likely due to heavy dust extinction along the l ine of sight causing the optical lines to underestimate the radial vel ocity. This dust must be located foreground to the region undergoing s olid body rotation.