Statistical properties of dark matter mini-haloes at z >= 15

Abstract

Understanding the formation of the first objects in the universe critically depends on knowing whether the properties of small dark matter structures at high-redshift (z > 15) are different from their more massive lower-redshift counterparts. To clarify this point, we performed a high-resolution N-body simulation of a cosmological volume 1 Mpc/h comoving on a side, reaching the highest mass resolution to date in this regime. We make precision measurements of various physical properties that characterize dark matter haloes (such as the virial ratio, spin parameter, shape, and formation times, etc.) for the high-redshift (z > 15) dark matter mini-haloes we find in our simulation, and compare them to literature results and a moderate-resolution comparison run within a cube of side-length 100 Mpc/h. We find that dark matter haloes at high-redshift have a log-normal distribution of the dimensionless spin parameter centered around λ $\sim$ 0.03, similar to their more massive counterparts. They tend to have a small ratio of the length of the shortest axis to the longest axis (sphericity), and are highly prolate. In fact, haloes of given mass that formed recently are the least spherical, have the highest virial ratios, and have the highest spins. Interestingly, the formation times of our mini-halos depend only very weakly on mass, in contrast to more massive objects. This is expected from the slope of the linear power spectrum of density perturbations at this scale, but despite this difference, dark matter structures at high-redshift share many properties with their much more massive counterparts observed at later times.

arXiv comment17 pages. Accepted for publication in MNRAS

References in corpus (48)

• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Planck 2013 results. XVI. Cosmological parameters
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
• Simulating the joint evolution of quasars, galaxies and their large-scale distribution
• Large scale bias and the peak background split
• Populating a cluster of galaxies - I. Results at z=0
• Profiles of dark haloes: evolution, scatter, and environment
• The Aquarius Project: the subhalos of galactic halos
• Concentrations of Dark Halos from their Assembly Histories
• Clustering of Galaxies in a Hierarchical Universe: I. Methods and Results at z=0
• Clumps and streams in the local dark matter distribution
• The statistics of LCDM Halo Concentrations
• Merger rates in hierarchical models of galaxy formation. II: Comparison with N-body simulations
• Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results
• The age dependence of halo clustering
• Transients from Initial Conditions in Cosmological Simulations
• The Shape of Dark Matter Halos: Dependence on Mass, Redshift, Radius, and Formation
• Simulations of Early Structure Formation: Primordial Gas Clouds
• One Hundred First Stars : Protostellar Evolution and the Final Masses
• The spin and shape of dark matter haloes in the Millennium simulation of a LambdaCDM universe
• Simulations on a Moving Mesh: The Clustered Formation of Population III Protostars
• Quantifying the heart of darkness with GHALO - a multi-billion particle simulation of our galactic halo
• Assembly bias in the clustering of dark matter haloes
• The halo mass function from the dark ages through the present day
• The Formation of Population III Binaries from Cosmological Initial Conditions
• Properties of galaxy dark matter halos from weak lensing
• Gravitational fragmentation in turbulent primordial gas and the initial mass function of Population III stars
• The Angular Momentum of Gas in Proto-Galaxies I. Implications for the Formation of Disk Galaxies
• Population III star formation in a Lambda CDM universe, I: The effect of formation redshift and environment on protostellar accretion rate
• A marked correlation function analysis of halo formation times in the Millennium Simulation
• Evidence for a Triaxial Milky Way Dark Matter Halo from the Sagittarius Stellar Tidal Stream
• Density profiles of LCDM clusters
• Direct measurement of dark matter halo ellipticity from two-dimensional lensing shear maps of 25 massive clusters
• Six Myths on the Virial Theorem for Interstellar Clouds
• The first generation of stars in LCDM cosmology
• The Effects of Accretion Luminosity upon Fragmentation in the Early Universe
• The Cosmogrid Simulation: Statistical Properties of Small Dark Matter Halos
• The Evolution of the Dark Halo Spin Parameters lambda and lambda' in a LCDM Universe: The Role of Minor and Major Mergers
• The Clustering of High Redshift Galaxies in the Cold Dark Matter Scenario
• First Structure Formation: A Simulation of Small Scale Structure at High Redshift
• The origin and tidal evolution of cuspy triaxial haloes
• How well do cosmological simulations reproduce individual-halo properties?
• Dark Matter Halo Environment for Primordial Star Formation
• Variation of the subhalo abundance in dark matter halos
• Angular momentum and clustering properties of early dark matter halos
• Virialization of high redshift dark matter haloes
• Spin and structural halo properties at high redshift in a LCDM Universe
• Dark matter merging induced turbulence as an efficient engine for gas cooling

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