The rotation curve of the Milky Way to 2 R(0)

A unified analysis of the Galactic rotation curve is presented using H I CO, and spectrophotometric data obtained in the northern hemisphere are used to determine the rotation curve from R = 3-17 kpc. A number of different functional forms are examined to fit the data, and the errors and uncertainties that go into its determination are discussed. The results are compared with nine recent studies of the rotation curve, and specific recommendations are made on the choice of curves to use in kinematic studies and mass modeling.