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In cosmological N-body simulations, the baryon effects on the cold dark matter (CDM) halos can be used to solve the small scale problems in $\Lambda$CDM cosmology, such as cusp-core problem and missing satellites problem. It turns out that…

Astrophysics of Galaxies · Physics 2017-08-02 Lin Wang , Da-Ming Chen

We present stellar and dark matter (DM) density profiles for a sample of seven massive, relaxed galaxy clusters derived from strong and weak gravitational lensing and resolved stellar kinematic observations within the centrally-located…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Andrew B. Newman , Tommaso Treu , Richard S. Ellis , David J. Sand

The significant diversity of rotation curve (RC) shapes in dwarf galaxies has recently emerged as a challenge to LCDM: in dark matter (DM) only simulations, DM halos have a universal cuspy density profile that results in self-similar RC…

The cusped NFW universal density profile suggested by typical CDM models has been challenged in recent years by the discoveries of the soft cores for a broad range of masses from dwarf galaxies to clusters of galaxies. It is thus desirable…

Astrophysics · Physics 2009-10-31 Xiang-Ping Wu , Yan-Jie Xue

We resolve the inner region of a massive cluster forming in a cosmological LCDM simulation with a mass resolution of 2*10^6 Msun and before z=4.4 even 3*10^5 Msun. This is a billion times less than the clusters final virial mass and a…

Astrophysics · Physics 2009-11-11 Juerg Diemand , Marcel Zemp , Ben Moore , Joachim Stadel , Marcella Carollo

Two well studied dwarf galaxies -- NGC 3109 and NGC 6822 -- present some of the strongest observational support for a flat core at the center of galactic dark matter (DM) halos. We use detailed cosmologically motivated numerical models to…

In the framework of the $\Lambda$CDM model, galaxies evolve within dark matter (DM) haloes, where baryonic processes modify the inner structure of the DM distribution. In particular, baryon condensation and feedback can alter the inner…

Astrophysics of Galaxies · Physics 2026-04-06 Vicente Honorato , Antonio D. Montero-Dorta , M. Celeste Artale , Ankit Kumar

Standard cosmology has many successes on large scales, but faces some fundamental difficulties on small, galactic scales. One such difficulty is the cusp/core problem. High resolution observations of the rotation curves for dark matter…

Astrophysics · Physics 2010-11-30 Da-Ming Chen , Stacy McGaugh

We developed a Deep Convolutional Neural Network (CNN), used as a classifier, to estimate photometric redshifts and associated probability distribution functions (PDF) for galaxies in the Main Galaxy Sample of the Sloan Digital Sky Survey…

Instrumentation and Methods for Astrophysics · Physics 2018-12-26 Johanna Pasquet , Emmanuel Bertin , Marie Treyer , Stéphane Arnouts , Dominique Fouchez

We derive the density profile of cold dark matter halos using a self-similar accretion model. We show that if the clumpiness of the infalling matter is taken into account, then the inner density slope, d(log{rho})/d(log{r}), is close to -1.…

Astrophysics · Physics 2007-05-23 Leonid Chuzhoy

The disparity between the density profiles of galactic dark matter haloes predicted by dark matter only cosmological simulations and those inferred from rotation curve decomposition, the so-called cusp-core problem, suggests that baryonic…

Astrophysics of Galaxies · Physics 2015-06-19 Peter R Hague , Mark I Wilkinson

We present a useful function for describing the profiles of dark-matter haloes with a varying asymptotic inner slope -\alpha, ranging from a cusp to a core, where the profiles of density, mass-velocity and potential are simple analytic…

Astrophysics of Galaxies · Physics 2016-10-06 Avishai Dekel , Guy Ishai , Aaron A. Dutton , Andrea V. Maccio

Dark-matter halos grown in cosmological simulations appear to have central NFW-like density cusps with mean values of $d\log\rho/d\log r \approx -1$, and some dispersion, which is generally parametrized by the varying index $\alpha$ in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-15 Jens Hjorth , Liliya L. R. Williams , Radosław Wojtak , Michael McLaughlin

Dwarf spheroidal galaxies (dSphs) are prime laboratories for studying dark matter (DM) and the black hole demographics in the low-mass regime. These systems are also often flattened; nevertheless most studies rely on spherical models,…

Astrophysics of Galaxies · Physics 2026-04-29 R. Pascale , G. Battaglia , J. M. Arroyo-Polonio , E. Vasiliev , C. Nipoti , G. F. Thomas

Distinguishing a core and a cusp within dark matter halos is complexified by the existence of mass-anisotropy degeneracy, where various combinations of velocity anisotropy ($\beta$) and inner density slope ($\gamma$) yield similar…

Astrophysics of Galaxies · Physics 2025-02-21 Dafa Wardana , Masashi Chiba , Kohei Hayashi

We explore the capability of deep learning to classify cosmic structures. In cosmological simulations, cosmic volumes are segmented into voids, sheets, filaments and knots, according to the distribution and kinematics of dark matter (DM),…

Astrophysics of Galaxies · Physics 2022-08-03 Shigeki Inoue , Xiaotian Si , Takashi Okamoto , Moka Nishigaki

Dark matter (DM) halos form hierarchically in the Universe through a series of merger events. Cosmological simulations can represent this series of mergers as a graph-like ``tree'' structure. Previous work has shown these merger trees are…

N-body simulations and analytical calculations of the gravitational collapse in an expanding universe predict that halos should form with a diverging inner density profile, the cusp. There are some observational indications that the dark…

Astrophysics · Physics 2009-11-06 Amr El-Zant , Isaac Shlosman , Yehuda Hoffman

Dwarf spheroidal galaxies have shallow central dark matter density profiles, low angular momentum and approximately exponential surface brightness distributions. Through N-body simulations and analytic calculations we investigate the extent…

Astrophysics · Physics 2009-11-10 J. I. Read , G. Gilmore

Every dark matter halo and subhalo is expected to have a prompt $\rho\propto r^{-1.5}$ central density cusp, which is a relic of its condensation out of the smooth mass distribution of the early universe. The sizes of these prompt cusps are…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-29 M. Sten Delos
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