On the axisymmetric thin disc model of flattened galaxies

Non-monotonic features of rotation curves, and also the related gravitational effects typical of thin discs – like backward-reaction or amplification of rotation by negative surface density gradients – which are characteristic imprints of disc-like mass distributions, are discussed in the axisymmetric thin disc model. The influence of the data cut-off in rotational velocity measurements on the determination of the mass distribution in flattened galaxies is studied. It has also been found that the baryonic matter distribution in the spiral galaxy NGC 5475, obtained in the axisymmetric thin disc approximation, accounts for the rotation curve of the galaxy. To obtain these results, the iteration method developed recently by the authors has been applied.