Related papers: A classical flow instability and its connection to…

In a series of papers, we propose a theory to explain the formation and properties of rings and spirals in barred galaxies. The building blocks of these structures are orbits guided by the manifolds emanating from the unstable Lagrangian…

Understanding the nature of spiral structure in disk galaxies is one of the main, and still unsolved questions in galactic astronomy. However, theoretical works are proposing new testable predictions whose detection is becoming feasible…

Over the last decade it has become clear that there is a decoupling between the old stellar disk and young stellar disk in spiral galaxies. This has led to a scheme for classifying galaxies on the basis of their near-infrared morphology.…

We investigate the formation of GMCs in spiral galaxies through both agglomeration of clouds in the spiral arms, and self gravity. The simulations presented include two-fluid models, which contain both cold and warm gas, although there is…

We present the numerical study of the formation of spiral structure in the context of violent relaxation. Initial conditions are the out-of-equilibrium disks of self-gravitating particles in rigid rotation. By that mechanism, robust and…

We study how well the complex gas velocity fields induced by massive spiral arms are modelled by the hydrodynamical simulations we used to constrain the dark matter fraction in nearby spiral galaxies (Kranz et al. 2001, 2003). More…

Motivated by recent observations of plateaus and minima in the radial abundance distributions of heavy elements in the Milky Way and some other spiral galaxies, we propose a dynamical mechanism for the formation of such features around…

The Magellanic Clouds are surrounded by an extended network of gaseous structures. Chief among these is the Magellanic Stream, an interwoven tail of filaments trailing the Clouds in their orbit around the Milky Way. When considered in…

Bars in spiral galaxies can weaken through gas inflow towards the center, and angular momentum transfer. Several bar episodes can follow one another in the life of the galaxy, if sufficient gas is accreted from the intergalactic medium to…

We present results concerning the internal structure and kinematics of disk galaxies formed in cosmologically motivated simulations. The calculations include dark matter, gas dynamics, radiative cooling, star formation, supernova feedback…

We study the formation of the spiral structure of barred spiral galaxies, using an $N$-body model. The evolution of this $N$-body model in the adiabatic approximation maintains a strong spiral pattern for more than 10 bar rotations. We find…

There are two theories of stellar spiral arms in isolated disc galaxies that model stellar spiral arms with different longevities: quasi-stationary density wave theory, which characterises spirals as rigidly rotating, long-lived patterns…

The phase spiral is a perturbation to the vertical phase-space distribution of stars in the Milky Way disk. We study the phase spiral's properties and how they vary with spatial position, in order to constrain its origin and evolution, as…

Large scale vortices could play a key role in the evolution of protoplanetary disks, particularly in the dead-zone where no turbulence associated with magnetic field is expected. Their possible formation by the subcritical baroclinic…

We present results from a detailed dynamical analysis of five high surface brightness, late type spirals, studied with the aim to quantify the luminous-to-dark matter ratio inside their optical radii. The galaxies' stellar light…

To probe the progenitors of the numerous massive spirals requires to dissect distant galaxy properties through spatially-resolved kinematics, detailed morphologies and photometry from UV to mid-IR. So far IMAGES is the only representative…

Pattern formation of a thin layer of vertically agitated wet granular matter is investigated experimentally. Due to the strong cohesion arising from the capillary bridges formed between adjacent particles, agitated wet granular matter…

We study the vertical perturbations in the galactic disc of the Milky Way-size high-resolution hydrodynamical cosmological simulation named GARROTXA. We detect phase spirals in the vertical projection $Z- V_{Z}$ of disc's stellar particles…

After a short review of the principal theories of spiral structure in galaxies, I describe two new developments. First, it now seems clear that linear theory cannot yield a full description for the development of spiral patterns because…

We present a hydrodynamical model of M33 and its recent interaction with M31. This scenario was previously proposed in the literature in order to explain the distorted gaseous and stellar disks of M33, as well as the increased star…