相关论文: The Angular Momentum Distribution within Halos in …
We use numerical simulations of critically-closed cold dark matter (CDM) models to study the effects of numerical resolution on observable quantities. We study simulations with up to $256^3$ particles using the particle-mesh (PM) method and…
Astrophysical observations spanning dwarf galaxies to galaxy clusters indicate that dark matter (DM) halos are less dense in their central regions compared to expectations from collisionless DM N-body simulations. Using detailed fits to DM…
We perform a series of high-resolution N-body simulations designed to examine the density profiles of dark matter halos. From 12 simulated halos ranging the mass of $2\times10^{12}\sim 5\times10^{14} h^{-1}{\rm M_\odot}$ (represented by…
We have analyzed high resolution N-body simulations of dark matter halos, focusing specifically on the evolution of angular momentum. We find that not only is individual particle angular momentum not conserved, but the angular momentum of…
The specific angular momentum of Cold Dark Matter (CDM) halos in a $\Lambda$CDM universe is investigated. Their dimensionless specific angular momentum $\lambda'=\frac{j}{\sqrt{2}V_{vir} R{vir}}$ with $V_{vir}$ and $R_{vir}$ the virial…
N-body simulations of Cold Dark Matter (CDM) have shown that, in this hierarchical structure formation model, dark matter halo properties, such as the density profile, the phase-space density profile, the distribution of axial ratio, the…
Context. The shapes of dark matter halos can be used to constrain the fundamental properties of dark matter. In standard Cold Dark Matter (CDM) cosmologies, halos are typically triaxial, with a preference for prolate configurations,…
We use N-body simulations of dark matter haloes in cold dark matter (CDM) and a large set of different warm dark matter (WDM) cosmologies to demonstrate that the spherically averaged density profile of dark matter haloes has a shape that…
We present new results on the angular momentum evolution of dark matter halos. Halos, from N-body simulations, are classified according to their mass growth histories into two categories: the accretion category contains halos whose mass has…
We compute the properties of dark matter halos with mass $10^{6.5}-10^9\msun$ at redshift $z=6-11$ in the standard cold dark matter cosmological model, utilizing a very high resolution N-body simulation. We find that dark matter halos in…
Cold Dark Matter with a large cosmological constant (LambdaCDM) appears to fit large scale structure observations well. Of the possible small scale problems, the Central Cusps and Too Many Satellites problems now appear to be at least…
We study the effects of mass and force resolution on the density profiles of galaxy-size Cold Dark Matter (CDM) halos in a flat, low-density cosmological model with vacuum energy. We show thatalthough increasing the mass and force…
We summarize recent developments in the study of the origin of halo spin profiles and preliminary implications on disk formation. The specific angular-momentum distributions within halos in N-body simulations match a universal shape, M(<j)…
The simple, conventional dark matter halo mass definitions commonly used in cosmological simulations ("virial" mass, FoF mass, $M_{50,100,200,...}$) only capture part of the collapsed material and are therefore inconsistent with the halo…
We study the mass, velocity dispersion, and anisotropy profiles of $\Lambda$CDM halos using a suite of N-body simulations of unprecedented numerical resolution (the {\it Aquarius Project}). Our analysis confirms a number of results claimed…
The near universality of DM halo density profiles provided by N-body simulations has proven to be robust against changes in total mass density, power spectrum, and some forms of initial velocity dispersion. In this letter we study the…
The central part of a dark matter halo reacts to the presence and evolution of a bar. Not only does the halo absorb angular momentum from the disk, it can also be compressed and have its shape modified. We study these issues in a series of…
In cosmological simulations without baryons, the relation between the specific angular momentum $j_{\rm h}$ and mass $M_{\rm h}$ of galactic dark matter halos has the well-established form $j_{\rm h} \propto M_{\rm h}^{2/3}$. This is…
I compare the density profile of dark matter (DM) halos in cold dark matter (CDM) N-body simulations with 1 Mpc, 32 Mpc, 256 Mpc and 1024 Mpc box sizes. In dimensionless units the simulations differ only for the initial power spectrum of…
We examine the properties of dark matter halos within a rich galaxy cluster using a high resolution simulation that captures the cosmological context of a cold dark matter universe. The mass and force resolution permit the resolution of 150…