| Abstract | NGC 3718 is an early type galaxy with a very peculiar optical appearance. The H I-distribution is very complex in the angular coordinates-velocity space. It can, however, be explained relatively simply by a strong warp, with parts of the orbits seen almost edge-on. The companion galaxy NGC 3729 is also detected in hydrogen. It has a systemic velocity 78 km s-1 higher than NGC 3718. Mass estimates of both galaxies are given and limits for the sum of masses of the galaxy pair are derived. There is weak evidence of an extended spiral arm or tidal bridge. The most likely explanation is that the warp is caused by captured gas that moves in a family of stable orbits, which are possible in a tumbling tri-axial potential (v. Albada et al., 1982, Merrit and de Zeeuw, 1983). |
