Radial profiles of NGC 2683. Upper panel: deprojected total (solid), atomic (dash-dotted), and assumed molecular (dashed) gas surface density based on SEST CO-line observations (see Sect. 4). The dotted line represents the symmetric deprojected Hi profile obtained from the method of Warmels (1988). Lower panel: observed and modeled rotation curve (solid), component due to the stellar bulge and disk (dashed), gas (dash-dotted), and dark matter halo (dotted). The colors indicate different K′ band mass-to-light ratios from blue (0.5) to red (1.3).