NGC 6181 is an isolated late-type giant spiral galaxy
whose high surface brightness
of gas emission and inclination of about 
are favorable
for a detailed kinematical study. Global parameters of the galaxy are
listed in Table 1 (click here) being taken basically from LEDA (Lyon-Meudon
Extragalactic Database). The first kinematical investigation of NGC
6181 was undertaken nearly 30 years ago by Burbidge et al.
(1965).
They obtained three spectral long-slit
cross-sections of the galaxy and found line-of-sight velocity
distributions to be quite asymmetrical. They concluded that NGC 6181
is not an axisymmetric galaxy being intermediate between a barred and
a normal spiral. The form of thin dust lanes in the center of NGC 6181
gave some support to this hypothesis. In addition, they noted that
``the structural center of the galaxy is not the center of the velocity
distribution", because the systemic velocities determined from the
outer and the inner parts of line-of-sight velocity curves disagreed.
Our group (Afanasiev et al. 1992) has repeated a long-slit
kinematical study of NGC 6181 at the 6m telescope of the Special Astrophysical
Observatory (SAO RAN) and fully confirmed the unusual asymmetrical
character of the one-dimensional line-of-sight velocity distributions.
It has been proposed that it is the southern part of the galaxy which
reveals strong non-circular gas motions up to distances of about
20
from the center. But it became evident that the obtaining of
the two-dimensional velocity field is necessary to clarify the situation.
Table 1: Global parameters of NGC 6181