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Most of the mass content of dark matter haloes is expected to be in the form of tidal debris. The density of debris is not constant, but rather can grow due to formation of caustics at the apocenters and pericenters of the orbit, or decay…

Astrophysics · Physics 2010-04-15 Niayesh Afshordi , Roya Mohayaee , Edmund Bertschinger

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

We present a model for the structure of the particle phase space average density ($P^2SAD$) in galactic haloes, introduced recently as a novel measure of the clustering of dark matter. Our model is based on the stable clustering hypothesis…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-05 Jesus Zavala , Niayesh Afshordi

(Context) In a Universe dominated by dark matter, halos are continuously accreting mass (violently or not) and such mechanism affects their dynamical state. (Aims) The evolution of dark matter halos in phase-space, and using the phase-space…

Astrophysics · Physics 2009-05-03 S. Peirani , J. A. de Freitas Pacheco

We study the phase-space structure of a dark-matter halo formed in a high resolution simulation of a Lambda CDM cosmology. Our goal is to quantify how much substructure is left over from the inhomogeneous growth of the halo, and how it may…

Astrophysics · Physics 2009-09-25 Amina Helmi , Simon D. M. White , Volker Springel

We explore observed dynamical trends in a wide range of dark matter dominated systems (about seven orders of magnitude in mass) to constrain hypothetical dark matter candidates and scenarios of structure formation. First, we argue that…

Astrophysics · Physics 2009-10-31 Julianne J. Dalcanton , Craig J. Hogan

We show that most particle and subhalo orbits in simulated cosmological cold dark matter halos are surprisingly regular and periodic: The phase space structure of the outer halo regions shares some of the properties of the classical…

Astrophysics · Physics 2009-11-13 J. Diemand , M. Kuhlen

We present a new formalism to study large-scale structure in the universe. The result is a hierarchy (which we call the "Helmholtz Hierarchy") of equations describing the phase space statistics of cold dark matter (CDM). The hierarchy…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-21 Svetlin Tassev

We estimate the two-point correlation function of dark matter haloes, with masses >10^{13} h^{-1} Mo, that have or not significant substructure. The haloes are identified with a friends of friends algorithm in a large LCDM simulation at two…

Astrophysics · Physics 2009-11-13 N. Espino-Briones , M. Plionis , C. Ragone-Figueroa

We use numerical simulations to examine the substructure within galactic and cluster mass halos that form within a hierarchical universe. Clusters are easily reproduced with a steep mass spectrum of thousands of substructure clumps that…

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

It has recently been proposed that if the Galactic dark matter halo were triaxial it would induce lumpiness in the velocity distribution of halo stars in the Solar Neighbourhood through orbital resonances. These substructures could…

Astrophysics of Galaxies · Physics 2018-04-12 Casper Hesp , Amina Helmi

The presence of dark matter substructure will boost the signatures of dark matter annihilation. We review recent progress on estimates of this subhalo boost factor---a ratio of the luminosity from annihilation in the subhalos to that…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-29 Shin'ichiro Ando , Tomoaki Ishiyama , Nagisa Hiroshima

Cosmological structure formation predicts that our galactic halo contains an enormous hierarchy of substructures and streams, the remnants of the merging hierarchy that began with tiny Earth mass microhalos. If these structures persist…

Astrophysics of Galaxies · Physics 2015-03-19 Aurel Schneider , Lawrence M. Krauss , Ben Moore

The hierarchical cold dark matter (CDM) model for structure formation is a well defined and testable model. Direct detection is the best technique for confirming the model yet predictions for the energy and density distribution of particles…

Astrophysics · Physics 2016-11-03 Ben Moore

The Cold Dark Matter paradigm successfully explains many phenomena on scales larger than galaxies, but seems to predict galaxy halos which are more centrally concentrated and have a lumpier substructure than observed. Endowing cosmic dark…

Astrophysics · Physics 2007-05-23 Craig J. Hogan

Cosmological models in which dark matter consists of cold elementary particles predict that the dark halo population should extend to masses many orders of magnitude below those at which galaxies can form. Here we report a cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-23 Jie Wang , Sownak Bose , Carlos S. Frenk , Liang Gao , Adrian Jenkins , Volker Springel , Simon D. M. White

In the cold dark matter model of structure formation, galaxies are assembled hierarchically from mergers and the accretion of subclumps. This process is expected to leave residual substructure in the Galactic dark halo, including partially…

Astrophysics · Physics 2009-11-06 D. Stiff , L. M. Widrow , J. Frieman

We present a new algorithm for identifying the substructure within simulated dark matter haloes. The method is an extension of that proposed by Tormen et al. (2004) and Giocoli et al. (2008a), which identifies a subhalo as a group of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Carlo Giocoli , Giuseppe Tormen , Ravi K. Sheth , Frank C. van den Bosch

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…

Astrophysics · Physics 2008-11-26 Toshiyuki Fukushige , Junichiro Makino
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