Related papers: Shape of the Galactic Orbits in Clusters
The morphology of clusters of galaxies may be described with a set of parameters which contain information about the formation and evolutionary history of these systems. In this paper we present a preliminary study of the morphological…
The disks of spiral galaxies are generally elliptical rather than circular. The distribution of ellipticities can be fit with a log-normal distribution. For a sample of 12,764 galaxies from the Sloan Digital Sky Survey Data Release 1 (SDSS…
We study the evolution of galaxies in clusters by the analysis of a sample of about 3000 galaxies, members of 59 clusters from the ESO Nearby Abell Cluster Survey (ENACS). We distinguish four cluster galaxy populations, based on their…
In this overview of the key properties of globular cluster (GC) systems I show that the GCs in elliptical and spiral host galaxies have more in common than previously thought. After contrasting these properties I briefly comment on GC…
Traditionally globular clusters and dwarf spheroidal galaxies have been distinguished by using one or more of the following criteria: (1) mass, (2) luminosity, (3) size, (4) mass-to-light ratio and (5) spread in metallicity. However, a few…
A growing number of Milky Way globular clusters have been identified to possess a noticeable degree of solid-body rotation. For several clusters, the combination of stellar proper motions and radial velocities allows for 3-dimensional spin…
Rotation curves of spiral galaxies are the major tool for determining the distribution of mass in spiral galaxies. They provide fundamental information for understanding the dynamics, evolution and formation of spiral galaxies. We describe…
A detailed analysis of the galaxy distribution in the Southern Sky Redshift Survey (SSRS) by means of the multifractal or scaling formalism is presented. It is shown that galaxies cluster in different ways according to their morphological…
The kinematical properties of elliptical galaxies formed during the mergers of equal mass, stars+gas+dark matter spiral galaxies are compared to the observed low velocity dispersions found for planetary nebulae on the outskirts of…
The velocity ellipsoid for 38 globular clusters with [Fe/H] <= -1.0 is derived and shown to be significantly anisotropic with major axis directed towards low Galactic latitude. Principal axes of the spatial distribution of different groups…
The velocity anisotropy of particles inside dark matter (DM) haloes is an important physical quantity, which is required for the accurate modelling of mass profiles of galaxies and clusters of galaxies. It is typically measured using the…
The globular clusters of the LMC are found to be significantly more elliptical than Galactic globular clusters, but very similar in virtually all other respects. The ellipticity of the LMC globular clusters is shown not be correlated with…
High-resolution numerical simulations of galaxy mergers are analysed. The global structure and isophotal shapes of the merger remnants are in good agreement with the observations. Whereas equal-mass mergers lead to anisotropic, boxy…
Different sequences of ellipsoids are represented on the ellipticity-rotation plane. The rotation parameter is defined as the ratio of kinetic energy related to the mean tangential equatorial velocity component to kinetic energy related to…
As a first step towards a comprehensive investigation of stellar motions within globular clusters, we present here the results of a study of stellar orbits in a mildly triaxial globular cluster that follows a circular orbit inside a galaxy.…
In nearby clusters early-type galaxies follow isotropic orbits, while the orbits of late-type galaxies are characterized by slightly radial anisotropy. Little is known about the orbits of the different populations of cluster galaxies at…
We study the distribution of projected ellipticity n(epsilon) for galaxies in a sample of 20 rich (Richness >= 2) nearby (z < 0.1) clusters of galaxies. We find no evidence of differences in n(epsilon), although the nearest cluster in the…
We investigate the velocity distribution of elliptical galaxies in the framework of Non-local Gravity. According to this approach, it is possible to recover the fundamental plane of elliptical galaxies without the dark matter hypothesis.…
Absolute proper motions for six new globular clusters have recently been determined. This motivated us to obtain the Galactic orbits of these six clusters both in an axisymmetric Galactic potential and in a barred potential, such as the one…
It is shown that the number of members, $N_A$, and the linear radius of the Abell clusters at $z<0.18$ increase with redshift. The increase is caused by observational selection: the number of rich and large clusters is small in the nearby…