Related papers: Probing the Environment with Galaxy Dynamics
This exploration of solutions for the orbits of Local Group galaxies under the cosmological initial condition of growing peculiar velocities and fitted to measured distances, redshifts, and proper motions reveals a considerable variety of…
We measure the effect of the environment on the intrinsic shapes of spiral and elliptical galaxies by finding the 3D shape distribution and dust extinction that fits better the projected shape of galaxies in different environment. We find…
Why do galactic bars rotate with high pattern speeds, when dynamical friction should rapidly couple the bar to the massive, slowly rotating dark halo? This longstanding paradox may be resolved by considering the dynamical interactions…
The formation process, properties, and spatial distribution of galaxy groups and clusters are closely related to the background cosmological model. We use numerical simulations of variants of the CDM model with different cosmological…
Evolution with mass segregation and the evolution of the rotation of cores are both discussed for self-similar core collapse. Evolution with angular velocity proportional to the square root of the density is predicted. On the Dynamical Main…
In hierarchical models, density fluctuations on different scales are correlated. This induces correlations between dark halo masses, their formation histories, and their larger-scale environments. In turn, this produces a correlation…
I review the properties of the Galaxy's stellar halo, specifically as traced by horizontal branch stars, but with reference to and in comparison with other stellar tracers. I discuss the halo density profile, the variation in horizontal…
The study of gas outside the plane of disc galaxies is crucial to understanding the circulation of material within a galaxy and between galaxies and the intergalactic environment. We present new HI observations of the edge-on galaxy NGC891,…
Some factors connecting the evolutionary histories of galaxies with the characteristics of their cluster systems are reviewed. Unanswered questions include: How is one to understand the observation that some globular cluster systems have…
The kinematics of satellite galaxies moving in a dark matter halo are a direct probe of the underlying gravitational potential. Thus, the phase-space distributions of satellites represent a powerful tool to determine the galaxy-halo…
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…
Ellipticals in very low density environments are extremely rare but hold important clues about galaxy formation and evolution. In this paper we continue our study of isolated elliptical galaxies, presenting results on the radial stellar…
According to the current paradigm, galaxies form and reside in extended cold dark matter (CDM) halos and in turn are key tracers of cosmological structure. Understanding how different types of galaxies occupy halos of different masses is…
Recent developments relevant to the formation of globular cluster systems in galaxies are discussed, including (1) The age distribution of the oldest Milky Way clusters, (2) Subgroups and possible accretion and merger remnants in the…
We review the origin and structure of hot (cooling flow) gas in elliptical galaxies. X-ray observations can be used to determine the stellar mass to light ratio, the mass profiles of dark matter halos, and the interstellar magnetic field.…
Evolution of galaxies is one of the most actual topics in astrophysics. Among the most important factors determining the evolution are two galactic components which are difficult or even impossible to detect optically: the gaseous disks and…
We present equations for the gravitational lensing flexion expected for an elliptical lens mass distribution. These can be reduced to one-dimensional finite integrals, thus saving significant computing time over a full two-dimensional…
In order to investigate the nature and origin of dust in elliptical galaxies, a method for the dust mass evaluation, which accounts for the dust temperature distribution, is here presented and discussed. The derived dust masses turn out to…
We investigated the evolution of clusters of galaxies using self-consistent $N$-body simulations in which each galaxy was modeled by many particles. We carried out simulations for about 20 cases using different initial conditions. In all…
Internal dynamical evolution can drive stellar systems into states of high central density. For many star clusters and galactic nuclei, the time scale on which this occurs is significantly less than the age of the universe. As a result,…