The Kinematics of Spiral and Irregular Galaxies

The present status of kinematical studies of intermediate- and late-type galaxies is reviewed. The emphasis is on observations that result in extensive maps of velocity fields rather than determinations of rotation curves from major axis observations only. The measurement of the distribution and kinematics of the gas is discussed, taking into account the methods of observation and velocity fields. Aspects of general rotation are examined and noncircular motions are considered. Attention is given to rotation curve shape and galaxy morphological type, rotation curves in the outer parts of spiral galaxies, velocity dispersion measurements, the central regions, large-scale effects of nuclear activity, bars and oval distortions, density wave streaming, warps in the outer parts of spiral galaxies, and the kinematical effects of tidal interactions.