Universal Merger Histories of Dark-Matter Haloes

Abstract

We study merger histories of dark-matter haloes in a suite of N-body simulations that span different cosmological models. The simulated cases include the up-to-date WMAP5 cosmology and other test cases based on the Einstein-deSitter cosmology with different power spectra. We provide a robust fitting function for the conditional mass function (CMF) of progenitor haloes of a given halo. This fit is valid for the different cosmological models and for different halo masses and redshifts, and it is a significant improvement over earlier estimates. Based on this fit, we develop a simple and accurate technique for transforming the merger history of a given simulated halo into haloes of different mass, redshift and cosmology. Other statistics such as main-progenitor history and merger rates are accurately transformed as well. This method can serve as a useful tool for studying galaxy formation. It is less sensitive to the low accuracy of the fit at small time-steps, and it can thus replace the more elaborate task of construction Monte-Carlo realizations. As an alternative approach, we confirm the earlier finding by Neistein & Dekel that the main-progenitor follows a log-normal distribution. This property of merger trees allows us to better capture their behaviour as a function of time and descendant mass, but a broader suite of simulations is required for evaluating the dependence of the log-normal parameters on the cosmological model.

Accepted for publication in MNRAS

References in corpus (19)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Toward a halo mass function for precision cosmology: the limits of universality
• Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results
• Accurate universal models for the mass accretion histories and concentrations of dark matter halos
• The halo mass function from the dark ages through the present day
• Natural Downsizing in Hierarchical Galaxy Formation
• The Excursion Set Theory of Halo Mass Functions, Halo Clustering, and Halo Growth
• The Nearly Universal Merger Rate of Dark Matter Haloes in Lambda-CDM Cosmology
• Is AGN feedback necessary to form red elliptical galaxies?
• Merger Rates of Dark-Matter Haloes
• The halo merger rate in the Millennium Simulation and implications for observed galaxy merger fractions
• Constructing Merger Trees that Mimic N-Body Simulations
• Environmental dependence in the ellipsoidal collapse model
• The statistical properties of LCDM halo formation
• The Dynamics of Subhalos in Warm Dark Matter Models
• How to Grow a Healthy Merger Tree
• Conditional Mass Functions and Merger Rates of Dark Matter Halos in the Ellipsoidal Collapse Model
• Multi-mass schemes for collisionless N-body simulations
• Merger history trees of dark matter haloes in moving barrier models

Cited by in corpus (18)

• The Redshift Evolution of LCDM Halo Parameters: Concentration, Spin, and Shape
• Balance among gravitational instability, star formation, and accretion determines the structure and evolution of disk galaxies
• On the origin of the fundamental metallicity relation and the scatter in galaxy scaling relations
• Coming of Age in the Dark Sector: How Dark Matter Haloes grow their Gravitational Potential Wells
• An analytical model for the accretion of dark matter subhalos
• What Sets the Sizes of the Faintest Galaxies?
• Stellar Mass--Gas-phase Metallicity Relation at $0.5\le z\le 0.7$: A Power Law with Increasing Scatter toward the Low-mass Regime
• What Do Dark Matter Properties Tell Us About Their Mass Assembly Histories?
• Towards a radially-resolved semi-analytic model for the evolution of disc galaxies tuned with machine learning
• Intelligent Design: On the Emulation of Cosmological Simulations
• Spin Flips - II. Evolution of dark matter halo spin orientation, and its correlation with major mergers
• Interaction between dark matter sub-halos & galactic gaseous disk
• Subhaloes gone Notts: the clustering properties of subhaloes
• Characterising the Structure of Halo Merger Trees Using a Single Parameter: The Tree Entropy
• Ram pressure profiles in galaxy groups and clusters
• The Degeneracy of Galaxy Formation Models
• Mass function and assembly of dark halos: an approach to inventory isolated overdense regions in random fields
• Excursion Sets with a "Perfect" Collapse Model