Related papers: Polygonal Structures in the Gaseous Disk: Numerica…
We have performed three-dimensional numerical simulations of accretion discs in a close binary system using the Smoothed Particle Hydrodynamics method. Our result show that, contrary to previous claims, 3D discs do exist even when the…
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…
It is generally assumed that gas in a galactic disk follows closely non self-intersecting periodic stellar orbits. In order to test this common assumption, we have performed MHD simulations of a galactic-like disk under the influence of a…
We consider a differentially rotating, 2D stellar disk perturbed by two steady state spiral density waves moving at different patterns speeds. Our investigation is based on direct numerical integration of initially circular test-particle…
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…
In this paper I describe numerical calculations of the motion of particles in a disk about a solar-mass object perturbed by a planet on a circular orbit with mass greater than 0.001 of the stellar mass. A simple algorithm for simulating…
The density-wave theory of spiral structure proposes that star formation occurs in or near a spiral-shaped region of higher density that rotates rigidly within the galactic disk at a fixed pattern speed. In most interpretations of this…
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…
The rotation dynamics of spiral galaxies is modeled using a sum of two mass distributions: a spherical bulge and a thin disk. The density functions representing these mass distributions are calculated from the total angular momentum of the…
We have observed an N-body/Smoothed Particle Hydrodynamics simulation of a Milky Way like barred spiral galaxy. We present a simple method that samples N-body model particles into mock Gaia stellar observations and takes into account…
The causes of spiral structure in galaxies remain uncertain. Leaving aside the grand bisymmetric spirals with their own well-known complications, here we consider the possibility that multi-armed spiral features originate from density…
Spiral structure is the most distinctive feature of disk galaxies and yet debate persists about which theory of spiral structure is the correct one. Many versions of the density wave theory demand that the pitch angle is uniquely determined…
We present a comprehensive series of $N$-body as well as $N$-body + SPH simulations to study the secular evolution of the structure of disk galaxies. Our simulations are organized in a hierarchy of increasing complexity, ranging from…
With the use of a background Milky-Way-like potential model, we performed stellar orbital and magnetohydrodynamic (MHD) simulations. As a first experiment, we studied the gaseous response to a bisymmetric spiral arm potential: the widely…
We perform axisymmetric hydrodynamical simulations that describe the nonlinear outcome of the viscous overstability in dense planetary rings. These simulations are particularly relevant for Cassini observations of fine-scale structure in…
We present local simulations that verify the linear streaming instability that arises from aerodynamic coupling between solids and gas in protoplanetary disks. This robust instability creates enhancements in the particle density in order to…
The current status of numerical simulations of galaxy formation is reviewed. After a short description of the main numerical simulation techniques, three sample applications illustrate how numerical simulations have provided deeper insight…
Results from kinematic observations of the central regions of spiral galaxies are reviewed, with particular emphasis on starburst and AGN hosts. While morphological studies lead to important insight, a more complete understanding of the…
We investigate turbulent gas motions in spiral galaxies and their importance to star formation in far outer disks, where the column density is typically far below the critical value for spontaneous gravitational collapse. Following the…
We investigate the influence of ram-pressure stripping on the internal gas kinematics of simulated spiral galaxies. Additional emphasis is put on the question of how the resulting distortions of the gaseous disc are visible in the rotation…