| Title | H I synthesis observations of the elliptical galaxy NGC 4278. |
| Authors | Raimond, E.; Faber, S. M.; Gallagher, J. S.; Knapp, G. R. |
| Bibcode | 1981ApJ...246..708R Search ADS ↗ |
| Abstract | The hydrogen-rich elliptical galaxy NGC 4278 has been mapped in 21 cm line radiation with the Westerbork Synthesis Radio Telescope. The hydrogen is distributed in an irregular ring within the optical galaxy with a minimum diameter of 15 kpc. The velocity field of the gas is rather regular and indicates ordered rotation about the central galaxy. However, the kinematic major and minor axes deviate from perpendicularity by 15 deg, indicating that noncircular motions are present. The new data confirm previous conclusions that the rotation of the outer gaseous ring is not coplanar with the rotation of the inner optical galaxy. The apparent skewing of the kinematic major and minor axes is most easily accounted for by assuming that the gas moves in oval orbits in a barred potential field. However, because the outer gas does not rotate like the inner galaxy, the origin of such a bar is uncertain. Alternatively, it may be a transient, nonequilibrium configuration resulting from the recent capture of a gas cloud or a dwarf irregular galaxy. A warp model and a model based on a tidal perturbation are also considered but look less attractive at the present time. |
| Objects | 1 Objects Search NED ↙ |
