相关论文: Can Massive Dark Haloes Destroy the Disks of Dwarf…
We investigate the Jeans instability of a galactic disk embedded in a dynamically responsive dark halo. It is shown that the disk-halo system becomes nominally Jeans unstable. On small scales the instability is suppressed, if the Toomre…
Aims: We want to investigate the growth of bar instability in stellar disks embedded in a suitable dark matter halo evolving in a fully consistent cosmological framework. Methods: We perform seven cosmological simulations to emphasise the…
The majority of disk galaxies manifest spirals and/or bars that are believed to result from dynamical instabilities. However, some galaxies have featureless disks, which are therefore inferred to be dynamically stable. Yet despite many…
Recent JWST observations claim the existence of a significant fraction of bars in the kinematically hotter and thicker disk at high redshift Universe. These observations challenge the current understanding of disk stability in galaxies…
We show that the exponential growth rate of a bar in a stellar disk is substantially greater when the disk is embedded in a live halo than in a rigid one having the same mass distribution. We also find that the vigor of the instability in…
The well-known bar instability of rotationally-supported disk galaxy models has been studied extensively since its first discovery over half a century ago. We were therefore very surprised to find cases of disks embedded in rigid halos,…
We use idealised N-body simulations of equilibrium discs in live and static haloes to study how dark matter co-evolution impacts the assembly of stellar particles into a bar and the halo response. Initial conditions correspond to a…
In this paper, we consider the problem of the evolution of the disk subsystem of galaxies in view of the halo. To this end, we have studied the dependence of the evolution of a non-linearly non-radially disk oscillating in its plane…
We explore a series expansion method to calculate the modes of oscillations for a variety of uniformly rotating finite disks, either with or without a dark halo. Since all models have the same potential, this survey focuses on the role of…
We confirm that a high rate of shear at the center is able to stabilize an entire stellar disk against bar-forming (m=2) modes, irrespective of the dark halo density. Our simulations of unstable power-law disks also yield the growth rate…
It has long been known that, in the absence of a dark matter (DM) halo, galaxy discs tend to develop global gravitational instabilities that strongly modify their initial structure. The recent discovery of gas-rich ultra diffuse galaxies…
We show that gas in a large fraction of low mass dark matter halos may form Toomre stable disks, if angular momentum is conserved when the gas contracts. Such halos would be stable to star formation and therefore remain dark. This may…
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…
The problem of how some disk galaxies avoid forming bars remains unsolved. Many galaxy models having reasonable properties continue to manifest vigorous instabilities that rapidly form strong bars and no widely-accepted idea has yet been…
The study presents a theoretical framework for understanding the role of dark matter on the stability of the galactic disc. We model the galaxy as a two-component system consisting of stars and gas in equilibrium with an external dark…
We present results of numerical N-body simulations of a galactic stellar disk embedded into a spherical dark halo. The non-linear dynamics of bending instabilities developing in the disk is studied. The bending modes, axisymmetric and not,…
While the total interior mass of a galaxy is reasonably well determined by a good rotation curve, the relative contributions from disk, bulge and halo are only weakly constrained by one-dimensional data. Barred galaxies are intrinsically…
In this review I concentrate on three areas related to structure of disks in spiral galaxies. First I will review the work on structure, kinematics and dynamics of stellar disks. Next I will review the progress in the area of flaring of HI…
High-quality optical rotation curves for a sample of low-luminosity spirals evidence that the dark halos around galaxies are inconsistent with the output of proper CDM simulations. In fact, dark halos enveloping stellar disks are structures…
The normal mode theory for warping of galaxy disks, in which disks are assumed to be tilted with respect to the equator of a massive, flattened dark halo, assumes a rigid, fixed halo. However, consideration of the back-reaction by a…