Related papers: Spiral Structure in Scale-free, Thin Discs: Rigid …
Spiral structure (both flocculent and Grand Design types) is very rarely observed in dwarf galaxies because the formation of spiral arms requires special conditions. In this work we analyze the sample of about 40 dS-galaxies found by…
In order to address the question of whether spiral disturbances in galaxy discs are gravitationally coupled to the halo, we conduct simulations of idealized models of disc galaxies. We compare growth rates of spiral instabilities in…
Most of the visible mass in a typical spiral galaxy is distributed in a thin disk, with a radial extent much larger than its thickness. While the planar disk structure, including non-axisymmetric features such as spiral structure, has been…
We investigate the effect of rotating, triaxial halos on disk galaxies through an extensive set of numerical N-body simulations. Our simulations use a rigid potential field for the halos and bulges and collisionless particles for the disks.…
We begin by recalling the isothermal, collisionless, disc-halo. The disc component is the Mestel disc. Subsequently we introduce spiral arms to such an isothermal disc-halo system that are co-moving in the mean with an axi-symmetric…
We describe methods for setting up self-consistent disk-bulge-halo galaxy models. The bulge and halo distribution functions (\df) are functions of $E$ and $L_z$ only. The halo's flattening and rotation can be specified. The disk \df\ is a…
Seven cosmological hydrodynamic simulations of disk galaxy formation are analyzed to determine the alignment of the disk within the dark matter halo and the internal structure of the halo. We find that the orientation of the outer halo,…
We employ very high resolution simulations of isolated Milky Way-like galaxies to study the effect of triaxial dark matter haloes on exponential stellar discs. Non-adiabatic halo shape changes can trigger two-armed grand-design spiral…
Within the standard hierarchical structure formation scenario, Milky Way-mass dark matter haloes have hundreds of dark matter subhaloes with mass $\gtrsim 10^8 \, {\rm M_{\odot}}$. Over the lifetime of a galactic disc a fraction of these…
In this paper we review the main and the most recent evidence for the presence of a core radius in the distribution of the dark matter around spiral galaxies. Their rotation curves, coadded according to the galaxy luminosity, conform to an…
Most fully developed galaxies have a vivid spiral structure, but the formation and evolution of the spiral structure are still an enigma in astrophysics. In this paper, according to the standard Newtonian gravitational theory and some…
The dynamics of a galactic disk in a non-axisymmetric (triaxial) dark halo is studied in detail using high-resolution, numerical, hydrodynamical models. A long-lived, two-armed spiral pattern is generated for a wide range of parameters. The…
Using $N$-body simulations ($N\sim 10^6 - 10^7$), we examine how a non-axisymmetric dark halo affects the dynamical evolution of the structure in collisionless (stellar) discs. We demonstrate how the model parameters such as mass of the…
Disk-halo decompositions of galaxy rotation curves are generally performed in a parametric way. We construct self-consistent models of nonspherical isothermal halos embedding a zero-thickness disk, by assuming that the halo distribution…
Using recent observational data, we construct a set of multi-component equilibrium models of the disk of a Milky Way-like galaxy. The disk dynamics are studied using collisionless-gaseous numerical simulations, based on the joined…
We present a new method for embedding a stellar disc in a cosmological dark matter halo and provide a worked example from a {\Lambda}CDM zoom-in simulation. The disc is inserted into the halo at a redshift z = 3 as a zero-mass rigid body.…
Observed scaling relations in galaxies between baryons and dark matter global properties are key to shed light on the process of galaxy formation and on the nature of dark matter. Here, we study the scaling relation between the neutral…
We suggest that the bulge-to-disc ratios of spiral galaxies are primarily determined by the angular momenta of their host haloes predicted in current hierarchical clustering models for structure formation. Gas with low specific angular…
We use a 380 h-1 pc resolution hydrodynamic AMR simulation of a cosmic filament to investigate the orientations of a sample of ~100 well-resolved galactic disks spanning two orders of magnitude in both stellar and halo mass. We find: (i) At…
We analyze the orbits of stars and dark matter particles in the halo of a disk galaxy formed in a cosmological hydrodynamical simulation. The halo is oblate within the inner ~20 kpc and triaxial beyond this radius. About 43% of orbits are…