Related papers: Velocity dispersion profile in dark matter halos
We present a precise estimate of the bulk virial scaling relation of halos formed via hierarchical clustering in an ensemble of simulated cold dark matter cosmologies. The result is insensitive to cosmological parameters, the presence of a…
The standard formalism for the co-evolution of halos and dark matter predicts that any initial halo velocity bias rapidly decays to zero. We argue that, when the purpose is to compute statistics like power spectra etc., the coupling in the…
By decomposing velocity dispersion into non-spin and spin-induced, mean flow and dispersion are analytically solved for axisymmetric rotating and growing halos. The polar flow can be neglected and azimuthal flow is directly related to…
We investigate the formation of virialized halos due to the gravitational collapse of collisionless matter using high-resolution N-body simulations. A variety of formation scenarios are studied, ranging from hierarchical clustering to…
We present stellar radial velocity data for the Draco dwarf spheroidal galaxy obtained using the AF2/WYFFOS instrument combination on the William Herschel Telescope. Our dataset consists of 186 member stars, 159 of which have good quality…
We study properties of dark matter halos at high redshifts z=2-10 for a vast range of masses with the emphasis on dwarf halos with masses 10^7-10^9 Msun/h. We find that the density profiles of relaxed dwarf halos are well fitted by the NFW…
Although N-body studies of dark matter halos show that the density profiles, rho(r), are not simple power-laws, the quantity rho/sigma^3, where sigma(r) is the velocity dispersion, is in fact a featureless power-law over ~3 decades in…
We study the distribution functions of mass and circular velocity for dark matter halos in N-body simulations of the $\Lambda$CDM cosmology, addressing redshift and environmental dependence. The dynamical range enables us to resolve…
We combine observed properties of galaxies as the core density and radius with the theoretical linear evolution of density fluctuations computed from first principles since the end of inflation till today. The halo radius r_0 is computed in…
Thanks to the ever increasing computational power and the development of more sophisticated algorithms, numerical N-body simulations are now uncovering several phenomenological relations between the physical properties of dark matter haloes…
We use a set of high-resolution simulations of scale-free Einstein-de Sitter cosmologies to investigate the logarithmic slope of the phase-space density profile $Q(r) = \rho(r)/\sigma^3(r)$ of dark matter (DM) haloes. The initial conditions…
We present a comprehensive series of dissipationless N-body simulations to investigate the evolution of density distribution in equal-mass mergers between dark matter (DM) halos and multicomponent galaxies. The DM halo models are…
Using the first 25% of DEEP2 Redshift Survey data, we probe the line-of-sight velocity dispersion profile for isolated galaxies with absolute B-band magnitude -22<M_B-5log(h)<-21 at z=0.7-1.0, using satellite galaxies as luminous tracers of…
We review the various techniques used to constrain the Galactic halo mass profile for radii > 20 kpc with particular emphasis on identifying a self-consistent halo model and resolving the apparent discrepancies present in the literature on…
We investigate the effect of a coupling between dark matter and dark energy on the rates for the direct detection of dark matter. The magnitude of the effect depends on the strength $\kappa$ of this new interaction relative to gravity. The…
There is good evidence from N-body simulations that the velocity distribution in the outer parts of halos is radially anisotropic, with the kinetic energy in the radial direction roughly equal to the sum of that in the two tangential…
We model the fastest moving (v_tot > 300 km/s) local (D < 3 kpc) halo stars using cosmological simulations and 6-dimensional Gaia data. Our approach is to use our knowledge of the assembly history and phase-space distribution of halo stars…
The annihilation of dark matter particles in the halo of galaxies may end up into gamma rays, which travel almost unperturbed till to their detection at Earth. This annihilation signal can exhibit an anisotropic behavior quantified by the…
Directional detection is an important way to detect dark matter. An input to these experiments is the dark matter velocity distribution. Recent hydrodynamical simulations have shown that the dark matter velocity distribution differs…
Dark-matter halos grown in cosmological simulations appear to have central NFW-like density cusps with mean values of $d\log\rho/d\log r \approx -1$, and some dispersion, which is generally parametrized by the varying index $\alpha$ in the…