Contributions to the theory of spiral structure. I - Energy and lifetime of density waves and the classification of spiral galaxies

Details Contributions to the theory of spiral structure. I - Energy and lifetime of density waves and the classification of spiral galaxies Contributions to the theory of spiral structure. I - Energy and lifetime of density waves and the classification of spiral galaxies

Aug 1980

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1980a%26a....88...41f&link_type=abstract

Astronomy and Astrophysics, vol. 88, no. 1-2, Aug. 1980, p. 41-51.

Astronomy and Astrophysics

Astrophysics

6

Astrophysics, Density Wave Model, Flux Density, Galactic Structure, Gas Dynamics, Spiral Galaxies, Energy Dissipation, Group Velocity, Interstellar Gas, Life (Durability), Wave Excitation

Scientific paper

The physical parameters of density waves in 25 well-known spiral galaxies of various types are investigated as a check on the density wave theory of spiral galaxy structure and in order to gain some understanding of the excitation mechanism. The lifetimes and energy densities of spiral waves of galaxies with known exact rotation curves and luminosity classes are calculated with consideration given to group velocity and energy dissipation on the basis of axisymmetric gas dynamics models of disk galaxies. Calculations show that the density wave, once excited, moves out of the galaxy within a time scale only 3.5 times the rotation period at corotation, and the galactic shock reduces this time scale by a factor of 3. The need for a powerful energy source (on the order of 30 erg/sq cm per year) is indicated. The spiral type is found to be almost uniquely determined by the wave energy density, which in turn is a function of the underlying mass distribution. Finally, the shock condition as measured by the gas velocity normal to the spiral arm correlates well with spiral type and luminosity class, which are also well correlated with the energy loss per shock.

Affiliated with

Also associated with

No associations

Rating

Contributions to the theory of spiral structure. I - Energy and lifetime of density waves and the classification of spiral galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Contributions to the theory of spiral structure. I - Energy and lifetime of density waves and the classification of spiral galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Contributions to the theory of spiral structure. I - Energy and lifetime of density waves and the classification of spiral galaxies will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1273308