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Related papers: Why are Halo Density Profiles Stable at Formation?

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Dark-matter halos are the scaffolding around which galaxies and clusters are built. They form when the gravitational instability of primordial density fluctuations causes regions which are denser than average to slow their cosmic expansion,…

Astrophysics · Physics 2007-05-23 Ilian T. Iliev , Paul R. Shapiro

We use explainable neural networks to connect the evolutionary history of dark matter halos with their density profiles. The network captures independent factors of variation in the density profiles within a low-dimensional representation,…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-22 Luisa Lucie-Smith , Hiranya V. Peiris , Andrew Pontzen

Dark-matter halos are the scaffolding around which galaxies and clusters are built. They form when the gravitational instability of primordial density fluctuations causes regions which are denser than average to slow their cosmic expansion,…

Astrophysics · Physics 2007-05-23 Paul R. Shapiro , Ilian T. Iliev , Hugo Martel , Kyungjin Ahn , Marcelo A. Alvarez

The growth-rate and the internal dynamics of galaxy-sized dark-matter haloes depend on their location within the cosmic web. Haloes that sit at the nodes grow in mass till the present time and are dominated by radial orbits. Conversely,…

Astrophysics of Galaxies · Physics 2017-06-21 Emilio Romano-Diaz , Enrico Garaldi , Mikolaj Borzyszkowski , Cristiano Porciani

Recent numerical studies of the dark matter density profiles of massive galaxy clusters ($M_{\rm halo} > 10^{15}$M$_{\odot}$) show that their median radial mass density profile remains unchanged up to $z > 1$, displaying a highly…

We have explored the dynamical and mass evolution of halos driven by large-scale filaments using a dark matter-only cosmological simulation with the help of a phase-space analysis. Since a non-negligible number of galaxies is expected to…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-18 Hannah Jhee , Hyunmi Song , Rory Smith , Jihye Shin , Inkyu Park , Clotilde Laigle

In this paper, we study the dynamical stability and time evolution of the central dark matter cores of low-mass (about 10^8-10^9 M_solar) galactic haloes found in recent cold dark matter simulations at high redshift. From those simulations…

Astrophysics · Physics 2009-11-10 Massimo Ricotti , Mark I. Wilkinson

The orbital parameters of dark matter (DM) subhaloes play an essential role in determining their mass-loss rates and overall spatial distribution within a host halo. Haloes in cosmological simulations grow by a combination of relatively…

Astrophysics of Galaxies · Physics 2021-02-17 Go Ogiya , James E. Taylor , Michael J. Hudson

I study the evolution of haloes density profiles as a function of time in the SCDM and LCDM cosmologies. Following Del Popolo et al. (1999), I calculate the concentration parameter c=r_v/a and study its time evolution. For a given halo…

Astrophysics · Physics 2009-10-31 A. Del Popolo

In the far future of an accelerating LCDM cosmology, the cosmic web of large-scale structure consists of a set of increasingly isolated halos in dynamical equilibrium. We examine the approach of collisionless dark matter to hydrostatic…

Astrophysics · Physics 2011-05-12 Michael T. Busha , August E. Evrard , Fred C. Adams , Risa H. Wechsler

We use the Illustris Simulations to gain insight into the build-up of the outer, low-surface brightness regions which surround galaxies. We characterize the stellar haloes by means of the logarithmic slope of the spherically-averaged…

In this paper, we analyse in detail the mass-accretion histories and structural properties of dark haloes in high-resolution N-body simulations. Modeling the density distribution in individual haloes with the NFW profile, we find, for all…

Astrophysics · Physics 2009-11-07 Donghai Zhao , Houjun Mo , Yipeng Jing , Gerhard Boerner

Navarro, Frenk, and White have suggested that the density profiles of simulated dark matter halos have a ``universal'' shape so that a given halo can be characterized by a single free parameter which fixes its mass. In this paper, we…

Astrophysics · Physics 2009-10-30 Richard N. Henriksen , Lawrence M. Widrow

We study the imprint of Dark Energy on the density profile of Dark Matter halos using a set of high-resolution large volume cosmological N-body simulations from the Dark Energy Universe Simulation Series (DEUSS). We first focus on the…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-03 Irène Balmès , Yann Rasera , Pier-Stefano Corasaniti , Jean-Michel Alimi

In this paper we calculate the density profiles of virialized halos both in the case of structure evolving hierarchically from a scale-free Gaussian delta-field having a power spectrum P(k)=A k^n in a Omega=1 Universe and in the case of the…

Astrophysics · Physics 2007-05-23 A. Del Popolo , M. Gambera , E. Recami , E. Spedicato

During hierarchical clustering, smaller masses generally collapse earlier than larger masses and so are denser on the average. The core of a small mass halo could be dense enough to resist disruption and survive undigested, when it is…

Astrophysics · Physics 2009-10-31 Kandaswamy Subramanian , Renyue Cen , Jeremiah P. Ostriker

Halos of similar mass and redshift exhibit a large degree of variability in their differential properties, such as dark matter, hot gas, and stellar mass density profiles. This variability is an indicator of diversity in the formation…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-20 Arya Farahi , Daisuke Nagai , Dhayaa Anbajagane

We propose a simple model that elucidates the generation of halo velocity bias. The fluid equation approximation is often adopted in modelling the evolution of the halo density field. In this approach, halos are often taken to be point…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-30 Kwan Chuen Chan

I apply the modified spherical infall model to test the dependence of the shape of density profiles of dark matter halos on redshift. The model predicts that the density profile of a halo of a given mass steepens with time and its…

Astrophysics · Physics 2007-05-23 Ewa L. Lokas

We utilize the Magneticum suite of hydrodynamical simulations to investigate the formation and evolution of cosmic voids from $z = 5.04$ to present day, using cold dark matter and (sub-) halo tracers in high-density samples. This includes…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-10 Nico Schuster , Nico Hamaus , Alice Pisani , Klaus Dolag , Jochen Weller