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Related papers: Modeling Angular-Momentum History in Dark-Matter H…

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The similarity between the distributions of spins for galaxies ($\lambda_{\rm g}$) and for dark-matter haloes ($\lambda_{\rm h}$), indicated both by simulations and observations, is naively interpreted as a one-to-one correlation between…

We develop a model for the growth of dark matter halos and use it to study their evolved density profiles. In this model, halos are spherical and form by quiescent accretion of matter in clumps, called satellites. The halo mass as a…

Astrophysics · Physics 2009-10-30 Adi Nusser , Ravi Sheth

Clusters, filaments, sheets and voids are the building blocks of the cosmic web. In this study, we present and compare two distinct algorithms for finding cosmic filaments and sheets, a task which is far less well established than the…

Astrophysics of Galaxies · Physics 2009-11-13 Youcai Zhang , Xiaohu Yang , Andreas Faltenbacher , Volker Springel , Weipeng Lin , Huiyuan Wang

In this paper we study the angular momentum properties of simulated dark matter halos at high redshift that likely host the first stars in the Universe. Calculating the spin distributions of these $10^6 - 10^7 \Msun$ halos in redshift…

Astrophysics · Physics 2009-11-13 Andrew J. Davis , Priyamvada Natarajan

Merger trees harvested from cosmological $N$-body simulations encode the assembly histories of dark matter halos over cosmic time, and are a fundamental component of semi-analytical models (SAMs) of galaxy formation. The ability to compare…

Astrophysics of Galaxies · Physics 2019-02-20 Rhys J. J. Poulton , Aaron S. G. Robotham , Chris Power , Pascal J. Elahi

Galaxies are believed to be in one-to-one correspondence with simulated dark matter subhalos. We use high-resolution N-body simulations of cosmological volumes to calculate the statistical properties of subhalo (galaxy) major mergers at…

Astrophysics · Physics 2009-11-13 Andrew R. Wetzel , J. D. Cohn , Martin White

The evolution of the spin parameter of dark halos and the dependence on the halo merging history in a set of dissipationless cosmological LCDM simulations is investigated. Special focus is placed on the differences of the two commonly used…

Astrophysics · Physics 2009-11-11 Helmut Hetznecker , Andreas Burkert

(Abridged) We report results of a series of non radiative N-body/SPH simulations in a LCDM cosmology. We find that the spin of the baryonic component is on average larger than that of the dark matter (DM) component and we find this effect…

Astrophysics · Physics 2009-11-10 Sanjib Sharma , Matthias Steinmetz

We model in simple terms the angular-momentum problems of galaxy formation in CDM cosmologies, and identify the key elements of a scenario that may solve them. The buildup of angular momentum is modeled via dynamical friction and tidal…

Astrophysics · Physics 2008-11-26 Ariyeh H. Maller , Avishai Dekel

Using a sample of 89 snapshots from 58 hydrodynamic binary galaxy major merger simulations, we find that stellar remnants are mostly oblate while dark matter halos are mostly prolate or triaxial. The stellar minor axis and the halo major…

Astrophysics · Physics 2009-11-11 Gregory S. Novak , Thomas J. Cox , Joel R. Primack , Patrik Jonsson , Avishai Dekel

The angular momentum properties of virialised dark matter haloes have been measured with good statistics in collisionless N-body simulations, but an equally accurate analysis of the baryonic spin is still missing. We employ the Illustris…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-18 Jolanta Zjupa , Volker Springel

The peak model of structure formation was built more than fifty years ago with the aim to address the origin of dark matter halo rotation in the tidal torque theory (TTT). Paradoxically, it has allowed one to explain and reproduce all halo…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-01 Eduard Salvador-Solé , Alberto Manrique

Galaxy formation and evolution models, such as semi-analytic models, are powerful theoretical tools for predicting how galaxies evolve across cosmic time. These models follow the evolution of galaxies based on the halo assembly histories…

Linking the properties of galaxies to the assembly history of their dark matter haloes is a central aim of galaxy evolution theory. This paper introduces a dimensionless parameter $s\in[0,1]$, the "tree entropy", to parametrise the geometry…

Astrophysics of Galaxies · Physics 2020-02-14 Danail Obreschkow , Pascal J. Elahi , Claudia del P. Lagos , Rhys J. J. Poulton , Aaron D. Ludlow

Anisotropy properties -- halo spin, shape, position offset, velocity offset, and orientation -- are an important family of dark matter halo properties that indicate the level of directional variation of the internal structures of haloes.…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-16 Kuan Wang , Philip Mansfield , Dhayaa Anbajagane , Camille Avestruz

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…

Astrophysics · Physics 2009-11-10 Elena D'Onghia , Andreas Burkert

We investigate the spins and shapes of over a million dark matter haloes identified at z=0 in the Millennium simulation. Our sample spans halo masses ranging from dwarf galaxies to rich galaxy clusters. The very large dynamic range of this…

Astrophysics · Physics 2008-11-26 Philip Bett , Vincent Eke , Carlos S. Frenk , Adrian Jenkins , John Helly , Julio Navarro

The balance of evidence indicates that individual galaxies and groups or clusters of galaxies are embedded in enormous distributions of cold, weakly interacting dark matter. These dark matter 'halos' provide the scaffolding for all luminous…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-26 James E. Taylor

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…

Astrophysics · Physics 2011-08-23 Andrew J. Benson

We test the Secondary Infall Model (SIM) by direct comparison with the results of N-body simulations. Eight cluster-size and six galactic-size dark matter haloes have been selected at $z=0$ and re-simulated with high resolution. Based on…

Astrophysics · Physics 2008-11-26 Y. Ascasibar , Y. Hoffman , S. Gottloeber