Related papers: Cosmological Velocity Bias
Comparing the gravitational acceleration induced on the Local Group of galaxies by different tracers of the underline density field we estimate, within the linear gravitational instability theory and the linear biasing ansatz, their…
Clusters and groups of galaxies are highly aspherical, with shapes approximated by nearly prolate ellipsoids of revolution. An equally fundamental property is the shape of these objects in velocity space which is the anisotropy of the…
We examine the effect of redshift space distortions on the galaxy two-point correlation function $\xi(r_p,\pi)$ as a function of separations parallel ($r_p$) and perpendicular ($\pi$) to the line of sight. We find that the relative velocity…
High-resolution N-body simulations are used to investigate systematic trends in the mass profiles and total masses of clusters as derived from 3 simple estimators: (1) the weak gravitational lensing shear field under the assumption of an…
We perform a statistical study of the global motion of cosmic voids using both a numerical simulation and observational data. We analyse their relation to large-scale mass flows and the physical effects that drive those motions. We analyse…
Galaxy cluster peculiar velocities can be inferred from high-sensitivity, high-resolution multiple-frequency observations in the 30 to 400 GHz range. While galaxy cluster counts and power spectra are sensitive to the growth factor, peculiar…
We investigate the power spectrum of velocity fluctuations in the universe, $V^2(k)$, starting from four different measures of velocity: (1) the power spectrum of velocity fluctuations from peculiar velocities of galaxies; (2) the rms…
The proper motions of stars in the outskirts of globular clusters are used to estimate cluster velocity dispersion profiles as far as possible within their tidal radii. We use individual color-magnitude diagrams to select high probability…
The relative velocity distribution of wide binary (WB) stars is sensitive to the law of gravity at the low accelerations typical of galactic outskirts. I consider the feasibility of this wide binary test using the `line velocity' method.…
We present radial velocities for 85 cool stars projected onto the central parsec of the Galaxy. The majority of these velocities have relative errors of $\sim$1 km/s, or a factor of $\sim$30-100 smaller than those previously obtained with…
Luminous tracers of large-scale structure are not entirely representative of the distribution of mass in our Universe. As they arise from the highest peaks in the matter density field, the spatial distribution of luminous objects is biased…
We show how the virial theorem can be applied to the hot gas in clusters of galaxies to obtain a yardstick, which could then be used to determine cosmological parameters. This yardstick relies on the assumptions of hydrostatic equilibrium…
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…
Dynamical parameters like average velocity dispersion and temperature profile of galaxy clusters are determined using a quasi equilibrium thermodynamic theory. The calculated velocity dispersion results from theory and simulations shows a…
We use a high resolution collisionless simulation of a Virgo--like cluster in a $\Lambda$CDM cosmology to determine the velocity and clustering properties of the diffuse stellar component in the intracluster region at the present epoch. The…
We investigate a sample of 14 galaxy clusters from the GOGREEN and GCLASS (GG) spectroscopic datasets within the redshift range $(0.87 \leq z \leq 1.37)$ and cluster masses $\mathrm{M}_{200} \gtrsim 2\times 10^{14}$ \hm. Using the highly…
We consider a run an tumble particle with two velocity states $\pm v_0$, in an inhomogeneous force field $f(x)$ in one dimension. We obtain exact formulae for its velocity $V_L$ and diffusion constant $D_L$ for arbitrary periodic $f(x)$ of…
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…
The velocity profile of galaxies around voids is a key ingredient for redshift space distortion (RSD) measurements made using the void-galaxy correlation function. In this paper we use simulations to test whether the velocity profile of the…
We investigate classical planetesimal accretion in a binary star system of separation ab<50AU by numerical simulations, with particular focus on the region at a distance of 1 AU from the primary. The planetesimals orbit the primary, are…