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相关论文: The Inner Structure of LambdaCDM Halos I: A Numeri…

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We investigate the structure of the dark matter halo formed in the cold dark matter scenario using $N$-body simulations. We simulated 12 halos with the mass of $6.6\times 10^{11}M_{\odot}$ to $8.0\times 10^{14}M_{\odot}$. In almost all…

天体物理学 · 物理学 2008-11-26 Toshiyuki Fukushige , Junichiro Makino

Generating pre-initial conditions (or particle loads) is the very first step to set up a cosmological N-body simulation. In this work, we revisit the numerical convergence of pre-initial conditions on dark matter halo properties using a set…

宇宙学与河外天体物理 · 物理学 2022-02-08 Tianchi Zhang , Shihong Liao , Ming Li , Jiajun Zhang

I use $N$-body simulations to investigate the morphology and the dynamical evolution and properties of dark matter halos in clusters of galaxies. My sample consists of nine massive halos, coming from an Einstein-de Sitter universe with…

天体物理学 · 物理学 2007-05-23 Giuseppe Tormen

We analyze the mass accretion histories (MAHs) and density profiles of cluster- size halos with virial masses of 0.6-2.5x10^14/h Msun in a flat LCDM cosmology. In agreement with previous studies,we find that the concentration of the density…

天体物理学 · 物理学 2008-11-26 Argyro Tasitsiomi , Andrey V. Kravtsov , Stefan Gottloeber , Anatoly A. Klypin

The $\Lambda$CDM model of structure formation makes strong predictions on concentration and shape of DM (dark matter) halos, which are determined by mass accretion processes. Comparison between predicted shapes and observations provides a…

宇宙学与河外天体物理 · 物理学 2018-06-13 Mauro Sereno , Keiichi Umetsu , Stefano Ettori , Jack Sayers , I-Non Chiu , Massimo Meneghetti , Jesús Vega-Ferrero , Adi Zitrin

We present the results from a series of collisionless N-body simulations of major mergers of galaxy dark matter haloes with density profiles having either inner cusps or cores. Our simulations range from 2x10^5 to 10^7 particles, allowing…

天体物理学 · 物理学 2009-11-10 Michael Boylan-Kolchin , Chung-Pei Ma

It has long been regarded as difficult for a cosmological model to account simultaneously for the galaxy luminosity, mass, and velocity distributions. We revisit this issue using a modern compilation of observational data along with the…

宇宙学与河外天体物理 · 物理学 2015-05-18 Sebastian Trujillo-Gomez , Anatoly Klypin , Joel Primack , Aaron J. Romanowsky

We study the scaling relations between dark matter (DM) haloes and galaxy discs using 175 galaxies from the SPARC database. We explore two cosmologically motivated DM halo profiles: the Einasto profile from DM-only simulations and the DC14…

星系天体物理 · 物理学 2018-11-14 Pengfei Li , Federico Lelli , Stacy S. McGaugh , Nathaniel Starkman , James M. Schombert

In order to specify cosmologically motivated initial conditions for major galaxy mergers (mass ratios $\leq$ 4:1) that are supposed to explain the formation of elliptical galaxies we study the orbital parameters of major mergers of cold…

天体物理学 · 物理学 2009-11-10 S. Khochfar , A. Burkert

We have identified over 2000 well resolved cluster halos, and also their associated bound subhalos, from the output of a 1024^3 particle cosmological N-body simulation (of box size 320 h^-1 Mpc and softening length 3.2 h^-1 kpc). This has…

天体物理学 · 物理学 2010-11-11 L. D. Shaw , J. Weller , J. P. Ostriker , P. Bode

Dark matter halo merger trees are now routinely extracted from cosmological simulations of structure formation. These trees are frequently used as inputs to semi-analytic models of galaxy formation to provide the backbone within which…

宇宙学与河外天体物理 · 物理学 2015-05-28 Andrew J. Benson , Stefano Borgani , Gabriella De Lucia , Michael Boylan-Kolchin , Pierluigi Monaco

We have combined the semi-analytic galaxy formation model of Guo et al. (2011) with the particle-tagging technique of Cooper et al. (2010) to predict galaxy surface brightness profiles in a representative sample of ~1900 massive dark matter…

We present distributions of the orbital parameters of dark matter substructures at the time of merging into their host halo. Accurate knowledge of the orbits of dark matter substructures is a crucial input to studies which aim to assess the…

天体物理学 · 物理学 2011-08-23 Andrew J. Benson

The internal dynamics of a dark matter structure may have the remarkable property that the local temperature in the structure depends on direction. This is parametrized by the velocity anisotropy beta which must be zero for relaxed…

[Abridged] The interaction rates of dark-matter halos and subhalos, are computed using high-resolution cosmological N-body simulations of the Lambda-CDM model. Although the number fraction of subhalos of mass $>2x10^{11}\hsolmass$ is only…

We explore the effects of small scale structure on the formation and equilibrium of dark matter halos in a universe dominated by vacuum energy. We present the results of a suite of four N-body simulations, two with a LCDM initial power…

天体物理学 · 物理学 2011-02-11 Michael T. Busha , August E. Evrard , Fred C. Adams

We propose a new numerical procedure to simulate a single dark halo of any size and mass in a hierarchical framework coupling the extended Press-Schechter formalism (EPSF) to N-body simulations. The procedure consists of assigning…

天体物理学 · 物理学 2009-11-07 Elena D'Onghia , Claudio Firmani , Guido Chincarini

Observations on galactic scales seem to be in contradiction with recent high resolution N-body simulations. This so-called cold dark matter (CDM) crisis has been addressed in several ways, ranging from a change in fundamental physics by…

天体物理学 · 物理学 2009-11-06 Alexander Knebe , Julien Devriendt , Asim Mahmood , Joseph Silk

According to the standard cold dark matter (CDM) cosmology, the structure of dark halos including those of galaxy clusters reflects their mass accretion history. Older clusters tend to be more concentrated than younger clusters. Their…

The Hypervelocity Star survey presents the currently largest sample of radial velocity measurements of halo stars out to 80 kpc. We apply spherical Jeans modeling to these data in order to derive the mass profile of the Galaxy. We restrict…

星系天体物理 · 物理学 2010-08-31 Oleg Y. Gnedin , Warren R. Brown , Margaret J. Geller , Scott J. Kenyon