The mass of the central body of the galaxy Ark 120 and the orbits of objects in its gravitational field.

Spectrograms of the Seyfert galaxy Ark 120 obtained in 1976-2013 are used to measure the radial velocities of emission features. It is assumed that these emission features with variable radial velocities are radiated by objects moving along Keplerian orbits in the gravitational field of the central body. Based on the available data, the parameters of the motion of three objects in the near-nuclear region of Ark 120 are calculated; the mass of its central body is estimated to be (1.675 ± 0.028) × 10 M. [ABSTRACT FROM AUTHOR]