Galactic rotation curve from OH survey

The Galactic rotation curve up to 16 kpc has been determined using the relation between parameters of OH molecular absorption features of the clouds and distance to the clouds. The data are presented separately for the galactocentric quadrants adjacent along the line connecting the Galactic center and the Sun. The rotation curve obtained follows kinematic behaviour of the Galaxy which has been determined from other interstellar molecules thus demonstrating the effective determination of distances to the molecular clouds in the Galaxy on the basis of observed hydroxyl aUsorption features. From the position of the central peak in the rotation curve the Sun galactocentric distance was estimated to be approximately8.5 kpc. The mass of the Galaxy interior to 100 kpc from the Galactic center is approximately3x1012 Msub(sun), as was derived from the rotational velocity distribution