The spiral-vortex structure of flat galaxies (prediction, theory, laboratoy and numerical experiments, observations)

Title:

The spiral-vortex structure of flat galaxies (prediction, theory, laboratoy and numerical experiments, observations)

Creator:

Afanasiev, V. L., P. V., Fridman, A. M., Ivchenko, I. N., Makov, Tu. N., Morozov, A. G., Nezlin, M. V., Pasha, I. I., Polyschenko, V. L., Rylov, A. Yu., Snezhkin, E. N., Torgashin, Yu. V., Trubnikov, A. S., and Zasov, A. V.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:594d997a-34c6-440c-a73c-e3e55d8a7fac
uuid:594d997a-34c6-440c-a73c-e3e55d8a7fac

Subject:

space research, flat galaxies, and spiral-vortex structures

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

Recent observations show a dip on the rotation curve for most of spiral galaxies,Theoretically, it implies that spiral density waves must be induced by shear instabilities,Calculations prove that the observed amount of gas In galactic disks (10% for the Galaxy) is sufficient to develop the hydrodynamical Instability in gas subsystems. As surface density perturbations of shallow water and galactic gas disks are described by the same equations, experiments with shallow water rotating slmilar to galactic disks have been made, In stationary stages of rotation stationary spiral pattems occur. The number of arms depends on the profile of rotation curve, in agreement with theoretical results, Different rotation parameters lead to different structures: the circular mode, one-, two-, ... , eight-armed spirals. Branching of the spirals is observed when rotation parameters change,which suggests that the spiral branching in several galaxies comes from their non-stationary rotation. Anticyclonic vortices are observed between the arms, Azimuthal averaging of the surface density, gives a good fit for the galaxy: minlmum of before the molecular ring, for realistic profiles of shallow water rotation the spirals are trailing, But they happen to lead for opposite directions of rotation of inner and outer regions, It may explain the leading spirals in galaxies whose spin is opposite either to that oft.blose companions or to the vector of orbital momentum of the pairs. Numerical computations confirm the theoretical and experimental results.They also show a formation like a "molecular ring". Preliminary observational data agree with these results.

Language:

Czech

Rights:

http://creativecommons.org/publicdomain/mark/1.0/
policy:public

Coverage:

301-306

Source:

Publications of the Astronomical Institute of the Academy of Sciences of the Czech Republic | 1987 Volume:63-70 | Number:69

Harvested from:

CDK

Metadata only:

false