The Rotation and Mass of the Inner Parts of NGC 4826.

In this paper we describe our attempt to measure the rotation of the Sb galaxy NGC 4826 The structure of this system is rather unusual; the outer part is composed of smooth stellar spiral arms and the inner dust lane seen over half of the galaxy is very prominent. Since ionized gas is found only in the dusty regions we have been able to measure the rotation and hence the mass distribution and mass only of these inner parts out to a radius of about 2 kpc. This mass turns out to be 1010 M0. The density-curve is very steep over this region If the density remained constant between 2 and 8 kpc, at the value it has at 2 kpc from the center, then the total mass would be about 10" M0.