Gas minor-axis velocity gradients in early-type spiral galaxies

We measured a remarkable gas velocity gradient along the minor axis of 5 early-type spiral galaxies. This phenomenon suggests the presence of a kinematically-decoupled component in orthogonal rotation with respect to the galaxy disk. If this is the case a second event has taken place in the history of the galaxy. Alternatively the gas velocity gradient is the result of non-circular motions induced by the potential of a triaxial bulge or of a bar