Related papers: Bending instabilities at the origin of persistent …
We perform controlled N-body simulations of disc galaxies growing within live dark matter (DM) haloes to present-day galaxies that contain both thin and thick discs. We consider two types of models: a) thick-disc initial conditions to which…
Some low surface brightness galaxies are known to have extremely thin stellar disks with the vertical to planar axes ratio 0.1 or less, often referred to as superthin disks. Although their existence is known for over three decades, the…
The majority of massive disk galaxies, including our own, have stellar bars with vertically thick inner regions -- so-called "boxy/peanut-shaped" (B/P) bulges. The most commonly suggested mechanism for the formation of B/P bulges is a…
Observations reveal that mature spiral galaxies consist of stars, gases and plasma approximately distributed in a thin disk of circular shape, usually with a central bulge. The rotation velocities quickly increase from the galactic center…
The evidence of the phenomenon for which, in galaxies, the gravitating mass is distributed differently than the luminous mass, increases as new data become available. Furthermore, this discrepancy is well structured and it depends on the…
Analyses of halo shapes for disc galaxies are said to give incongruous results. I point out that the modified dynamics (MOND) predicts for disc galaxies a distribution of fictitious dark matter that comprises two components: a pure disc and…
We report the results of self-gravitating simulations of spiral galaxies, modeled by stellar and gaseous components, developed to investigate in particular the role of dissipation in the evolution of galaxy disks. The gas disk is simulated…
Observations show that about the 20% of the Universe is composed by invisible (dark) matter (DM), for which many candidates have been proposed. In particular, the anomalous behavior of rotational curves of galaxies (i.e. the flattening at…
An accurate knowledge of the dark matter distribution in the Milky Way is of crucial importance for galaxy formation studies and current searches for particle dark matter. In this paper we set new dynamical constraints on the Galactic dark…
The lopsidedness of galaxies is a commonly observed phenomenon, and through different studies, it has been observed that nearly 30% of galaxies show this phenomenon. In this work, we study morphological lopsidedness in both stellar and gas…
(Abridged) Axisymmetric models of the Milky Way exhibit strong interrelations between the Galactic constants (R_0 and T_0), the stellar columndensity (S_*) and the shape of the dark matter (DM) halo. Here we present analytical relations…
We present robust constraints from the Sloan Digital Sky Survey (SDSS) on the shape and distribution of the dark matter halo within the Milky Way (MW). Using the number density distribution and kinematics of SDSS halo stars, we probe the…
A parameterized model of the mass distribution within the Milky Way is fitted to the available observational constraints. The most important single parameter is the ratio of the scale length R_d* of the stellar disk to R0. The disk and…
In a previous paper (Paper I) a method was developed to determine the shapes of dark matter halos of spiral galaxies from the flaring and velocity dispersion of the gas layer. Here I present the results for the almost edge-on Scd galaxy NGC…
We use N-body simulations of bar formation in isolated galaxies to study the effect of bulge mass and bulge concentration on bar formation. Bars are global disk instabilities that evolve by transferring angular momentum from the inner to…
We study gravitational instabilities in disks, with special attention to the most massive clumps that form because they are expected to be the progenitors of globular-type clusters. The maximum unstable mass is set by rotation and depends…
Using observational data on the kinematical properties and density distributions of the subsystems of the Milky Way galaxy, we construct a set of multi-component equilibrium models of its disk. The dynamics of the disk is studied…
We study gravitational instabilities in disks, with special attention to the most massive clumps that form because they are expected to be the progenitors of globular-type clusters. The maximum unstable mass is set by rotation and depends…
We explore the growth and the evolution of the bar instability in stellar-gaseous disks embedded in a suitable dark matter halo evolving in a fully consistent cosmological framework. The aim of this paper is to point out the impact of…
We investigated a hydrostatic equilibrium model of the Milky Way following Parker (1966), to constrain the large scale properties of the interstellar medium. In our approach we found an excellent agreement between our simple hydrostatic…