Related papers: Triplets of Galaxies: Some Dynamical Aspects
In some galaxies, the central velocity dispersion, sigma, is depressed with respect to the surroundings. This sigma-drop phenomenon may have different physical origins, bearing information about the internal dynamics of the host galaxy. In…
The kinematics of the outer parts of three intermediate-luminosity elliptical galaxies have been studied using the Planetary Nebula Spectrograph. The galaxies' velocity dispersion profiles are found to decline with radius; dynamical…
Many stars do not live alone, but instead have one or more stellar companions. Observations show that these binaries, triples and higher-order multiples are common. Whereas the evolution of single stars and binaries have been studied…
The kinematics of newly-formed star clusters are interesting both as a probe of the state of the gas clouds from which the stars form, and because they influence planet formation, stellar mass segregation, cluster disruption, and other…
Hierarchical triple stars are ideal laboratories for studying the interplay between orbital dynamics and stellar evolution. Both stellar wind mass loss and three-body dynamics cooperate to destabilise triples, which can lead to a variety of…
The comparison between dynamical mass and lensing mass provides a targeted test for a wide range of modified gravity models. In our previous paper we showed, through numerical simulations, that the measurement of the line-of-sight velocity…
We discuss the nature of the velocity dispersion vs. size relation for molecular clouds. In particular, we add to previous observational results showing that the velocity dispersions in molecular clouds and cores are not purely functions of…
We calculated the median values of the following parameters for 87 groups of galaxies with three to eight components: the mean rms velocity of the galaxies in the group, S_v = 166 km/s; the harmonic mean radius, R_h = 29 kpc; and the…
In massive objects, such as galaxy clusters, the turbulent velocity dispersion, $\sigma_\mathrm{turb}$, is tightly correlated to both the object mass, $M$, and the thermal energy. Here, we investigate whether these scaling laws extend to…
There is a general agreement that galaxy structures exhibit fractal properties, at least up to some small scale. However the presence of an eventual crossover towards homogenization, as well as the exact value of the fractal dimension, are…
To reveal small galaxy groups in the Local Supercluster, a new approach is suggested which allows for individual properties of galaxies. The criterion is based on the assumption of closed motions of companions around the dominating group…
Current understanding of the secular evolution of galactic disks suggests that this process is dominated by two or more heating mechanisms, which increase the random motions of stars in the disk. In particular, the gravitational influence…
A small fraction of galaxies appear to reside in dense compact groups, whose inferred crossing times are much shorter than a Hubble time. These short crossing times have led to considerable disagreement about the dynamical state of these…
We develop a simple, fast and predictive model of the hierarchical formation of galaxies which is in quantitative agreement with observations. Comparing simulations with observations we place constraints on the density of the universe and…
We use a state-of-the-art semi-analytic model to study the size and the specific angular momentum of galaxies. Our model includes a specific treatment for the angular momentum exchange between different galactic components. Disk scale radii…
Radial velocity dispersion in spheroidal and elliptical galaxies, as a function of radial distance from the center of the galaxy, has been derived from Cosmological Special Relativity. For velocity dispersions in the outer regions of…
Deep surveys conducted during the past decades have shown that galaxies in the distant universe are generally of more irregular shapes, and are disky in appearance and in their star formation rate, compared to galaxies in similar…
This is a short note on the spatiotemporal complexity of the dynamical state(s) of the universe at subhorizon scales (up to 300 Mpc). There are reasons, based mainly on infrared radiative divergences, to believe that one can encounter a…
We identify isolated galaxy triplets in a volume-limited sample from the Sloan Digital Sky Survey Data Release 10. Our final sample has 80 galaxy systems in the redshift range 0.04$\le$z$\le$0.1, brighter than $M_r = -20.5 + 5\log h_{70}$.…
The use of the tensor virial theorem (TVT) as a diagnostic of anisotropic velocity distributions in galaxies is revisited. The TVT provides a rigorous global link between velocity anisotropy, rotation and shape, but the quantities appearing…