ROTATION AND VELOCITY DISPERSION IN THE STELLAR COMPONENT OF NGC-1316 (FORNAX-A)

Observations have been made of the stellar kinematics in NGC 1316, the galaxy associated with the strong radio source FornaxA. The galaxy is rotating rapidly about its photometric minor axis. A jump in the radial velocity of approximately 30 km s-1 is found along the major axis at the position of the first ripple in the luminosity profile. The velocity dispersion decreases from a nuclear value of 230 km s-1 to about 180 km s-1 at the first ripple, remaining approximately constant at larger radii. The data are consistent with the galaxy being an oblate spheroid flattened by rotation, with isotropic velocity dispersion. The presence of the radial velocity step agrees with the hypothesis that NGC 1316 is the result of at least one merger between a disc and an elliptical galaxy. © Royal Astronomical Society • Provided by the NASA Astrophysics Data System.