Related papers: Density waves in the inner parts of disk galaxies
Density waves in the central kpc of galaxies, taking the form of spirals, bars and/or lopsided density distributions are potential actors of the redistribution of angular momentum. They thus play an important role in the overall evolution…
In this paper, I mention a few processes which may play a role in the evolution of the central regions of galaxies. In this context, I briefly discuss some issues regarding the formation of bulges in spirals, the role of supermassive black…
Bars play a major role in driving the evolution of disk galaxies and in shaping their present properties. They cause angular momentum to be redistributed within the galaxy, emitted mainly from (near-)resonant material at the inner Lindblad…
I present here an heterogeneous selection of nearby galaxies in which inner density waves (bars, spirals, m=1 modes) have been observed, and which are presumed to host a supermassive black hole, to illustrate the importance of such inner…
Bars and spiral arms have played an important role as constraints on the dynamics and on the distribution of dark matter in the optical parts of disk galaxies. Dynamics linked to the dissipative nature of gas, and its transformation into…
Spiral patterns are important agents of galaxy evolution. In this review, I describe how the redistribution of angular momentum by recurrent transient spiral patterns causes the random speeds of stars to rise over time, metallicity…
Angular momentum redistribution within barred galaxies drives their dynamical evolution. Angular momentum is emitted mainly by near-resonant material in the bar region and absorbed by resonant material mainly in the outer disc and in the…
In the past two decades, secular evolution has emerged as an important new paradigm for the formation and evolution of the Hubble sequence of galaxies. A new dynamical mechanism was identified through which density waves in galaxies, in the…
Complex plasmas consist of microparticles embedded in a low-temperature plasma and allow investigating various effects by tracing the motion of these microparticles. Dust density waves appear in complex plasmas as self-excited acoustic…
This chapter reviews theoretical work on the stellar dynamics of galaxy disks. All the known collective global instabilities are identified, and their mechanisms described in terms of local wave mechanics. A detailed discussion of warps and…
The gas component plays a major role in the dynamics of spiral galaxies, because of its dissipative character, and its ability to exchange angular momentum with stars in the disk. Due to its small velocity dispersion, it triggers…
A theory is developed for the dynamics of eccentric perturbations $[\propto \exp(\pm i\phi)]$ of a disk galaxy residing in a spherical dark matter halo and including a spherical bulge component. The disk is represented as a large number $N$…
In this review, I discuss just three aspects of the stability and evolution of galactic discs. (1) I first review our understanding of the bar instability and how it can be controlled. Disc galaxies in which the orbital speed does not…
We analyze formation of grand-design two-arm spiral structure in the nuclear regions of disk galaxies. Such morphology has been recently detected in a number of objects using high-resolution near-infrared observations. Motivated by the…
The organization of the interstellar medium in disk galaxies obeys the large scale dynamics set by kpc-size structures. Improving our knowledge of how the dense, molecular gas is distributed in a disk is an important step in our…
Spirals in galaxies have long been thought to be caused by gravitational instability in the stellar component of the disk, but discerning the precise mechanism had proved elusive. Tidal interactions, and perhaps bars, may provoke some…
The central kpc of barred galaxies exhibits a wealth of morphological information on different components with clear dynamical consequences. These include nuclear rings, spirals, bars, and more. We argue that this morphology is driven by…
The radial distribution of mass in a disk galaxy is strongly constrained by its rotation curve. The separate contributions from the individual stellar populations and dark matter (DM) are not easily disentangled, however, especially since…
Observations reveal that mature spiral galaxies consist of stars, gases and plasma approximately distributed in a thin disk of circular shape, usually with a central bulge. The rotation velocities quickly increase from the galactic center…
Some 30% of disc galaxies have a pronounced central bar feature in the disc plane and many more have weaker features of a similar kind. Kinematic data indicate that the bar constitutes a major non-axisymmetric component of the mass…