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相关论文: On the spin distributions of $\Lambda$CDM haloes

200 篇论文

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 present a numerical study of dark matter halo concentrations in $\Lambda$CDM and self-similar cosmologies. We show that the relation between concentration, $c$, and peak height, $\nu$, exhibits the smallest deviations from universality…

宇宙学与河外天体物理 · 物理学 2015-01-21 Benedikt Diemer , Andrey V. Kravtsov

We present that the spin$-$orbit alignment (SOA; i.e., the angular alignment between the spin vector of a halo and the orbital angular momentum vector of its neighbor) provides an important clue to how galactic angular momenta develop. In…

星系天体物理 · 物理学 2020-06-03 Sung-Ho An , Juhan Kim , Jun-Sung Moon , Suk-Jin Yoon

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…

天体物理学 · 物理学 2009-10-30 Adi Nusser , Ravi Sheth

The concentration parameter is a key characteristic of a dark matter halo that conveniently connects the halo's present-day structure with its assembly history. Using 'Dark Sky', a suite of cosmological $N$-body simulations, we investigate…

By decomposing velocity dispersion into non-spin and spin-induced, mean flow and dispersion are analytically solved for axisymmetric rotating and growing halos. The polar flow can be neglected and azimuthal flow is directly related to…

星系天体物理 · 物理学 2022-07-15 Zhijie Xu

Theoretical frameworks based on Press-Schechter formalism and excursion set arguments suggest that the abundance of dark matter haloes exhibits universal behaviour when expressed in terms of peak height. If true, this implies that a single…

宇宙学与河外天体物理 · 物理学 2025-07-02 Yuhao Li , Robert E. Smith

In a recent paper arXiv:0709.0299, we introduced a spin expansion that provides a simple yet powerful way to understand aspects of binary black hole (BBH) merger. This approach relies on the symmetry properties of initial and final…

天体物理学 · 物理学 2008-11-26 Latham Boyle , Michael Kesden

A modified version of the extended Press-Schechter model for the growth of dark-matter haloes was introduced in two previous papers with the aim at explaining the mass-density relation shown by haloes in high-resolution cosmological…

天体物理学 · 物理学 2009-11-07 A. Raig , G. Gonzalez-Casado , E. Salvador-Sole

We estimate halo spins for HI-rich galaxies in the Arecibo Legacy Fast Alfa Survey using a semi-analytic approach, examining the relationship between halo spin and stellar surface density. Our findings reveal an inverse correlation in both…

星系天体物理 · 物理学 2024-11-28 Yu Rong , Zichen Hua , Huijie Hu

We use numerical simulations to investigate how the statistical properties of dark matter (DM) haloes are affected by the baryonic processes associated with galaxy formation. We focus on how these processes influence the spin and shape of a…

宇宙学与河外天体物理 · 物理学 2015-06-05 S. E. Bryan , S. T. Kay , A. R. Duffy , J. Schaye , C. Dalla Vecchia , C. M. Booth

Leveraging the semi-analytic method, we compute halo spins for a substantial sample of HI-bearing galaxies observed in the Arecibo Legacy Fast Alfa Survey. Our statistical analysis reveals a correlation between halo spin and environment,…

星系天体物理 · 物理学 2025-03-10 Zichen Hua , Yu Rong , Huijie Hu

We consider black holes resulting from binary black hole mergers. By fitting to numerical results we construct analytic formulas that predict the mass and spin of the final black hole. Our formulas are valid for arbitrary initial spins and…

广义相对论与量子宇宙学 · 物理学 2008-11-26 Wolfgang Tichy , Pedro Marronetti

Any measurement made using an N-body simulation is subject to noise due to the finite number of particles used to sample the dark matter distribution function, and the lack of structure below the simulation resolution. This noise can be…

星系天体物理 · 物理学 2017-08-16 Andrew J. Benson

We present the Synthetic UniveRses For Surveys ({\sc surfs}) simulations, a set of N-body/Hydro simulations of the concordance $\Lambda$ Cold Dark Matter (\LCDM) cosmology. These simulations use Planck cosmology, contain up to 10 billion…

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…

We have constructed the merging history of dark matter halos in a SCDM cosmology, by means of a the {``Merging Cell Model''} (Rodrigues & Thomas 1996). It is based on the linear theory of growth of density fluctuations, and the Top-Hat…

天体物理学 · 物理学 2007-05-23 Barbara Lanzoni , Gary A. Mamon , Bruno Guiderdoni

We calculate by means of the Press-Schechter formalism the density profile developed by dark-matter halos during accretion, i.e., the continuous aggregation of small clumps. We find that the shape of the predicted profile is similar to that…

天体物理学 · 物理学 2009-11-07 Alberto Manrique , Andreu Raig , Eduard Salvador-Sole , Teresa Sanchis , Jose M. Solanes

We study the concentration parameters, their mass dependence and redshift evolution, of dark-matter halos in different dark-energy cosmologies with constant and time-variable equation of state, and compare them with "standard'' Lambda-CDM…

We calculate merger rates of dark matter haloes using the Extended Press-Schechter approximation (EPS) for the Spherical Collapse (SC) and the Ellipsoidal Collapse (EC) models. Merger rates have been calculated for masses in the range…

宇宙学与河外天体物理 · 物理学 2012-08-03 Nicos Hiotelis