Differential rotation of the inner metagalaxy.

Radial velocities of external galaxies are examined to see if there is evidence indicating a differential rotation of the observed system of galaxies about a center beyond the reach of our telescopes. The theory of differential rotation of Oort and Lindblad is extended to apply to this problem. The space distribution of 38 galaxies with distances from 0.2 X 106 to 1.6 X 106 parsecs is such that our galaxy is at one end of an ellipsoidal agglomeration. The peculiar motion of our galaxy is found to be 179 km/sec toward the center of this group (1 = 1050, b = 390), and a K term of the order of 600 km/sec per 106 parsecs is derived. It is therefore concluded that these nearby galaxies are receding from our galaxy, but because of their' asymmetrical space distribution, the peculiar motion of our galaxy into the group is sufficient to mask the presence of the linear expansion. The effects of a differential rotation are negligible at this distance. Analysis of the radial velocities of 70 galaxies with distances in the range from 1.6 X 106 to 4.0 X 106 parsecs indicates a K term of 612 km/ sec per 106 parsecs, and a peculiar motion of our galaxy of 373 km/sec toward 1 = 1600, b = 220. The pole of the rotational plane of the system is placed at 1 = 140, b = 100, and the center of rotation, indeterminate by 1800, at 1 = 1040, b = 50, or 1 = 2840, b = A, the change in radial velocity produced by rotation, is of the order of I0- km/sec per parsec of distance from our galaxy. The following are estimated to be a consistent, though not necessarily unique, set of constants of the universe: Radius of the universe I0 parsecs Mass of the universe 1021 solar masses Distance of our galaxy from center of rotation I0 parsers Rotational velocity of our galaxy 1000 km/sec. Department of Astronomy, Cornell University, Ithaca, N. Y.