Spectrum and structure of large-scale oscillations of the galactic gas layer

The perturbations of the polytropic gaseous layer are studied taking into account the rotation in the gravitational field of the spheroidal stellar component of the Galaxy. The spectrum of large- and small-scale oscillations of the layer and the corresponding spatial structures of perturbations are obtained. The possibilities of interpreting the observed large-scale structures of the gaseous layer of the Galaxy as normal modes of the layer oscillations are discussed.