Related papers: Radial Mixing in Galactic Discs
The evolution of circumstellar discs is influenced by their surroundings. The relevant processes include external photoevaporation due to nearby stars, and dynamical truncations. The impact of these processes on disc populations depends on…
We analyse a high-resolution, fully cosmological, hydrodynamical disc galaxy simulation, to study the source of the double-exponential light profiles seen in many stellar discs, and the effects of stellar radial migration upon the…
The accretion disk around a rotating magnetic star (neutron star, white dwarf or T Tauri star) is subjected to periodic vertical magnetic forces from the star, with the forcing frequency equal to the stellar spin frequency or twice the spin…
When present, extended disks of neutral hydrogen around spiral galaxies show a remarkably uniform velocity dispersion of approx 6 km/s. Since stellar winds and supernovae are largely absent in such regions, neither the magnitude nor 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…
Nearly all of the initial angular momentum of the matter that goes into each forming star must somehow be removed or redistributed during the formation process. The possible transport mechanisms and the possible fates of the excess angular…
Stellar migration is an important dynamical process in Galactic disk. Here we model the radial stellar migration in the Galactic disk with an analytical method, then add it to detailed Galactic chemical evolution model to study the…
As stars traverse the Milky Way, their orbits evolve through perturbations that alter their orbital radii. These changes arise from two mechanisms: churning, which modifies angular momentum, and blurring, which induces eccentric orbits…
The early stages of a galaxy's evolution leave an imprint on its metallicity distribution. We discuss the origins and evolution of radial metallicity gradients in discs of spiral galaxies using an analytical chemical evolution model. We…
We consider models of gas flow in spiral galaxies in which the spiral structure has been excited by various possible mechanisms: a global steady density wave, self-gravity of the stellar disc and an external tidal interaction, as well as…
Large-scale warps in the outer parts of spiral galaxy discs have been observed for almost forty years, but their origin remains obscure. We review the dynamics of warped galaxy discs. We identify several mechanisms that could excite warps,…
Differential rotation plays a key role in stellar evolution by triggering hydrodynamical instabilities and large-scale motions that induce transport of chemicals and angular momentum and by modifying the propagation and the frequency…
The redistribution of stars in galactic disks is an important aspect of disk galaxy evolution. Stars that efficiently migrate in such a way that does not also appreciably heat their orbits can drastically affect the stellar populations…
Recent knowledge of Galactic dynamics suggests that stars radially move on the disk when they encounter transient spiral arms that are naturally generated during the process of disk formation. We argue that a large movement of the solar…
Recent work on the mass distribution in spiral galaxies, using mainly HI observations, is reviewed. The principal problem is still to determine to what extent the dark matter is important in the inner parts of a galaxy, or in other words,…
We investigate the dynamical effects of a molecular cloud complex with a mass of about 10**7 M_sun and a size of a few 100 pc on the vertical distribution of stars and atomic hydrogen gas in a spiral galactic disc. Such massive complexes…
We test the effect of assumptions about stellar motion on the behavior of gravitational instabilities in protoplanetary disks around solar-type stars by performing two simulations that are identical in all respects except the treatment of…
We summarize the results obtained from our suite of chemical evolution models for spiral disks, computed for different total masses and star formation efficiencies. Once the gas, stars and star formation radial distributions are reproduced,…
Internal gravity waves (IGWs) can cause mixing in the radiative interiors of stars. We study this mixing by introducing tracer particles into two - dimensional (2D) hydrodynamic simulations. Following the work of Rogers & McElwaine (2017),…
Circumstellar asymmetries such as central warps have recently been shown to cast shadows on outer disks. We investigate the hydrodynamical consequences of such variable illumination on the outer regions of a transition disk, and the…