Mass Distribution and Physical Conditions in the Inner Region of NGC 1068.

Rotational velocities in the spiral nebula NGC 1065 have been measured out to a distance of about 25" (2000 pc) from the center on two spectra with the slit in P.A. 57 and 5S . The very broad emission lines arising in the nucleus prevent measurement of rotation in the central region. The two rotation- curves are linear with distance along the slit and have the same slope; the position angle of the line of intersection of the plane of the galaxy with the plane of the sky can be determined from the slopes of two rotation-curves and in this case lies midway between the slit orientations. By assuming that the mass interior to the farthest measured velocity is distributed over a uniform spheroid with c/a = 0.2, this mass is determined from the rotation-curves to be 2.7 X 1010 M0. The mass-to-light ratio is 2, and the escape velocity at the center is 410 km/sec. By adding arbitrary masses in similar spheroids situated inside the first spheroid and computing the resulting velocity-curves, it is shown that the mass cannot be increased even by 10 per cent for the same value of c/a. The centers of gravity of the broad nuclear emission lines are shifted to the violet by about 300 km/sec with respect both to the central points of the narrow rotationally inclined emission lines in the outer part and to the stellar Ca ii K line in the nucleus. Seyfert has shown that the average velocity spread of the nuclear emission lines is 1450 km/sec. This is more than three times the escape velocity at the center. These facts lead to the conclusion that gas is being ejected from the nucleus of this galaxy at high velocities. Some discussion is given of the possible implication of these results. The situation bears some resemblance to the observation of the ejection of gas from the nucleus of our own Galaxy.