The Rotation Curve Of The Milky Way to 2 R sub o

The rotation curve of the Milky Way is determined for galactocentric distances between 3 kpc and 17 kpc using inner and outer Galaxy data sets and a simple function to represent the data. H I tangent point velocities are used inside the solar circle; CO velocities and spectrophotometric distances of associated H II regions are used in the outer Galaxy. A variety of functional forms for the rotation curve and various assumptions about the velocity field and the objects observed are tested.