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Related papers: A Model For Infall Around Virialized Halos

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The observed flaring of HI disk in the outer region of galaxies has been used in the past to determine the shape of the dark matter halo. Previous studies based on this concept suggest a slightly oblate halo (axis ratio ~ 0.8) for our…

Astrophysics · Physics 2009-11-11 C. A. Narayan , K. Saha , C. J. Jog

(Abridged) We study the outer density profiles of dark matter haloes predicted by a generalized secondary infall model and observed in a N-body cosmological simulation of a \Lambda CDM model. We find substantial systematic variations in…

Astrophysics · Physics 2009-10-31 V. Avila-Reese , C. Firmani , A. Klypin , A. V. Kravtsov

In a serie of three papers, the dynamical interplay between environments and dark matter haloes is investigated, while focussing on the dynamical flows through their virial sphere. Our method relies on both cosmological simulations, to…

Astrophysics · Physics 2008-11-26 Dominique Aubert , Christophe Pichon

We present a precise estimate of the bulk virial scaling relation of halos formed via hierarchical clustering in an ensemble of simulated cold dark matter cosmologies. The result is insensitive to cosmological parameters, the presence of a…

The first dark matter halos form by direct collapse from peaks in the matter density field, and evidence from numerical simulations and other analyses suggests that the dense inner regions of these objects largely persist today. These halos…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-24 M. Sten Delos , Margie Bruff , Adrienne L. Erickcek

We measure the clustering of dark matter halos in a large set of collisionless cosmological simulations of the flat LCDM cosmology. Halos are identified using the spherical overdensity algorithm, which finds the mass around isolated peaks…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Jeremy L. Tinker , Brant E. Robertson , Andrey V. Kravtsov , Anatoly Klypin , Michael S. Warren , Gustavo Yepes , Stefan Gottlober

In two previous papers (Salvador-Sol\'e 2012a,b), it was shown that: i) the typical structural and kinematic properties of haloes in (bottom-up) hierarchical cosmologies endowed with random Gaussian density perturbations of dissipationless…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-20 Eduard Salvador-Solé , Sinue Serra , Alberto Manrique

Mass around dark matter halos can be divided into "infalling" material and "collapsed" material that has passed through at least one pericenter. Analytical models and simulations predict a rapid drop in the halo density profile associated…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-31 Eric Baxter , Chihway Chang , Bhuvnesh Jain , Susmita Adhikari , Neal Dalal , Andrey Kravtsov , Surhud More , Eduardo Rozo , Eli Rykoff , Ravi K. Sheth

This paper constructs an analytic framework for calculating the assembly of galactic disks from the collapse of gas within dark matter halos, with the goal of determining the surface density profiles. Gas parcels (baryons) fall through the…

Astrophysics · Physics 2008-11-26 Fred C. Adams , Anthony M. Bloch

In a recent paper, Salvador-Sol\'e et al. (2012) have derived the typical inner structure of dark matter haloes from that of peaks in the initial random Gaussian density field, determined by the power-spectrum of density perturbations…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-13 Eduard Salvador-Solé , Sinue Serra , Alberto Manrique Guillermo González-Casado

The initial radial density profiles of dark matter halos are laid down by gravitational collapse in hierarchical structure formation scenarios and are subject to further compression as baryons cool and settle to the halo centers. We here…

Astrophysics · Physics 2009-11-13 J. A. Sellwood , Stacy S. McGaugh

Although high-resolution N-body simulations make robust empirical predictions for the density distribution within cold dark matter halos, these studies have yielded little physical insight into the origins of the distribution. We…

Astrophysics · Physics 2008-11-26 Liliya L. R. Williams , Arif Babul , Julianne J. Dalcanton

An analytical model for the postcollapse equilibrium structure of virialized objects which condense out of the cosmological background universe is described and compared with observations and simulations of cosmological halos. The model is…

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

We study the density profiles of collapsed galaxy-size dark matter halos with masses 1e11-5e12 Msun focusing mostly on the halo outer regions from the formal virial radius Rvir up to 5-7Rvir. We find that isolated halos in this mass range…

Recently there has been a lot of attention focussed on a virialized halo-based approach to understanding the properties of the matter and galaxy power spectrum. A key ingredient in this model is the number and distribution of galaxies…

Astrophysics · Physics 2009-10-31 Martin White , Lars Hernquist , Volker Springel

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

We present the germ of a new model for High Velocity Clouds, derived from the idea that the dark matter halo of our Galaxy is in the form of cold, planetary-mass gas clouds. In this picture HVCs arise as a result of disruptive collisions…

Astrophysics · Physics 2007-05-23 Mark Walker , Mark Wardle

It is common practice to describe formal size and mass scales of dark matter halos as spherical overdensities with respect to an evolving density threshold. Here, we critically investigate the evolutionary effects of several such commonly…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Marcel Zemp

In this proceeding, we briefly review three recent results. First, we show that halos formed in simulations with gas cooling are significantly rounder than halos formed in dissipationless $N$-body simulations. The increase in principle axis…

Astrophysics · Physics 2016-11-03 Andrew R. Zentner , Savvas M. Koushiappas , Stelios Kazantzidis

Among the most fundamental properties of a dark matter halo is its density profile. Motivated by the recent proposal by Garc\'ia et al. [R. Garc\'ia et. al., MNRAS 521, 2464 (2023)] to define a dynamical halo as the collection of orbiting…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-02 Tristen Shields , Edgar M. Salazar , Eduardo Rozo , Aakanksha Adya , Calvin Osinga , Ze'ev Vladimir