Unstable spiral modes in disk-shaped galaxies.

  title={Unstable spiral modes in disk-shaped galaxies.},
  author={Yue Ying Lau and C. C. Lin and James W.-K. Mark},
  journal={Proceedings of the National Academy of Sciences of the United States of America},
  volume={73 5},
  • Y. Lau, C. Lin, J. Mark
  • Published 1 May 1976
  • Physics
  • Proceedings of the National Academy of Sciences of the United States of America
The mechanisms for the maintenance and the excitation of trailing spiral modes of density waves in diskshaped galaxies, as proposed by Lin in 1969 and by Mark recently, are substantiated by an analysis of the gas-dynamical model of the galaxy. The self-excitation of the unstable mode in caused by waves propagating outwards from the corotation circle, which carry away angular momentum of a sign opposite to that contained in the wave system inside that circle. Specifically, a simple dispersion… 
On a general fluid dynamical theory of discrete unstable spiral modes in disk-shaped galaxies
Abstract A general fluid dynamical theory of discrete unstable spiral modes in disk-shaped galaxies is described. This formulation of modes includes a radiation boundary condition and an exact
Density Wave Theory of Spiral Structure of Galaxies
Summary The density-wave theory of spiral structure in galaxies is studied as a dynamical problem: the gravitational instability of a galactic disk with respect to spiral modes. The asymptotic theory
Spiral‐vortex structures generation in gaseous galactic disks with a two‐hump rotation curve
The hydrodynamic (HD) global modes of oscillations in thin gaseous disks of solitary flat galaxies are numerically investigated. The unstable HD modes are shown to be generated in the gaseous disk
The nearby spiral density-wave structure of the Galaxy: Line-of-sight and longitudinal velocities of 61 masers
This paper is the eighth in a series presenting the results of the dynamical analysis of velocity fields of Galactic objects on the assumption that the system is subject to moderately unstable,
Six Decades of Spiral Density Wave Theory
The theory of spiral density waves had its origin approximately six decades ago in an attempt to reconcile the winding dilemma of material spiral arms in flattened disk galaxies. We begin with the
Effect of inner Lindblad resonance on spiral density waves propagation in disc galaxies: reflection over absorption
Interaction of spiral density waves with stars in the vicinity of the inner Lindblad resonance in galactic discs is investigated using the linear perturbation theory and the leading orders in the
Self-consistent models of spiral galaxies
The shape and extend of spiral patterns in galaxies depend on both physical and dynamical properties of their disks. The study of self-consistent models of spiral galaxies and the comparison with
Stability of a finite disc under the influence of a spherical halo
We have studied the stability of finite gaseous discs, against large-scale perturbations, under the influence of spherical, massive haloes. A surface-density distribution consistent with the observed
Dawes Review 4: Spiral Structures in Disc Galaxies
  • C. Dobbs, J. Baba
  • Physics
    Publications of the Astronomical Society of Australia
  • 2014
Abstract The majority of astrophysics involves the study of spiral galaxies, and stars and planets within them, but how spiral arms in galaxies form and evolve is still a fundamental problem. Major
A Theory of Bending Waves with Applications to Disk Galaxies
A theory of bending waves is surveyed which provides an explanation for the required amplification of the warp in the Milky Way. It also provides for self-generated warps in isolated external