Related papers: On the Structural Differences between Disk and Dwa…
Dwarf galaxies have attracted increased attention in recent years, because of their susceptibility to galaxy transformation processes within rich galaxy clusters. Direct evidence for these processes, however, has been difficult to obtain,…
Recent observations suggest that dwarf galaxies pervade the universe, for they have been encountered in large numbers in all the environments. However, we present evidence that suggests dwarf galaxies may be subject to strong dynamical…
The origin of metal-rich, highly flattened, and rapidly rotating disk globular cluster system in the Galaxy is one of longstanding issues in the context of the Galaxy formation. Our numerical simulations suggest a new ``two-fold'' scenario…
Recent observations demonstrate that the thin and thick disks of the Galaxy have different chemical abundance trends and evolution timescales. The relative abundances of $\alpha$-elements in the thick Galactic disk are increased relative to…
Recent years have seen a series of large-scale photometric surveys with the aim of detecting substructure in nearby dwarf galaxies. Some of these objects display a varying distribution of each stellar population, reflecting their star…
Recent observations have reported that some gas-rich dwarf irregular (dIrr) galaxies appear to have spherical distributions in the outer underlying old and intermediate-age stellar populations (e.g., NGC 6822). These observations imply that…
This is a summary of a general discussion held during the third EuroConference on galaxy evolution. Various observational features of the stellar populations in present--day dwarf galaxies were presented to introduce the discussion on the…
The formation of galactic discs and the efficiency of star formation within them are issues central to our understanding of galaxy formation. We have developed a detailed and versatile model of disc formation which combines the strengths of…
The separation of the Milky Way disk into a thin and thick component is supported by differences in the spatial, kinematic and metallicity distributions of their stars. These differences have led to the view that the thick disk formed early…
Galaxies, in particular disc galaxies, contain a number of structures and substructures with well defined morphological, photometric and kinematic properties. Considerable theoretical effort has been put into explaining their formation and…
Correlations between stellar kinematics and chemical abundances are fossil evidence for evolutionary connections between Galactic structural components. Extensive stellar surveys show that the only tolerably clear distinction between…
The severity of the mass discrepancy in spiral galaxies is strongly correlated with the central surface brightness of the disk. Progressively lower surface brightness galaxies have ever larger mass discrepancies. No other parameter…
The formation mechanism of high-concentration dwarf galaxies is still a mystery. We perform a comparative study of the intrinsic shape of nearby low-mass galaxies with different stellar concentration. The intrinsic shape is parameterized by…
We summarize the properties of tidal dwarf candidates in a sample of interacting galaxies and classify objects in tidal tails depending on their morphological appearance. New high-resolution dynamical models are needed to understand how the…
We investigate the role of stellar mass in shaping the intrinsic thickness of galaxy discs by determining the probability distribution of apparent axis ratios (b/a) for two different samples that probe the faint end of the galaxy luminosity…
Dwarf galaxies are ideal laboratories to test dark matter models and alternative theories because their dynamical mass (from observed kinematics) largely outweighs their baryonic mass (from gas and stars). In most star-forming dwarfs, cold…
We examine whether early-type galaxies in clusters may have evolved from later types by the fading of their disks (e.g., as a result of ram-pressure stripping or strangulation) or by enhancement of the bulge luminosity (e.g., due to tidal…
The mass discrepancy in disk galaxies is shown to be well correlated with acceleration, increasing systematically with decreasing acceleration below a critical scale a0 = 3700 km^2/s^2/kpc = 1.2E-10 m/s/s. For each galaxy, there is an…
We study the evolution of disk galaxies using galaxy evolutionary models with initial and boundary conditions linked to the hierarchical formation scenario. Disks galaxies are modeled locally within growing cold dark matter halos and…
By means of interferometic 21-cm observations and a 3D kinematic modeling technique, we study the gas kinematics of six HI-rich ultra-diffuse galaxies (UDGs). We derive robust circular velocities and baryonic masses, that allow us to study…