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We construct axisymmetric mass models for dwarf spheroidal (dSph) galaxies in the Milky Way to obtain plausible limits on the non-spherical structure of their dark halos. This is motivated by the fact that the observed luminous parts of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Kohei Hayashi , Masashi Chiba

I report recent results of numerical simulations designed to study the inner structure of Cold Dark Matter (CDM) halos. This work confirms the proposal of Navarro, Frenk & White (NFW) that the shape of LambdaCDM halo mass profiles differs…

Astrophysics · Physics 2007-05-23 Julio F. Navarro

We introduce a novel implementation of orbit-based (or Schwarzschild) modeling that allows dark matter density profiles to be calculated non-parametrically in nearby galaxies. Our models require no assumptions to be made about velocity…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 John R. Jardel , Karl Gebhardt , Maximilian Fabricius , Niv Drory , Michael J. Williams

In the present paper, we improve the "Extended Secondary Infall Model" (ESIM) of Williams et al. (2004) to obtain further insights on the cusp/core problem. The model takes into account the effect of ordered and random angular momentum,…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-04 A. Del Popolo , P. Kroupa

We provide the first direct lifting of the mass/anisotropy degeneracy for a cluster of galaxies, by jointly fitting the line of sight velocity dispersion and kurtosis profiles of the Coma cluster, assuming an NFW tracer density profile, a…

Astrophysics · Physics 2007-05-23 Gary A. Mamon , Ewa L. Lokas , Teresa Sanchis

We provide a ``Baedecker'' or travel guide to the directions on the sky where the dark matter annihilation signal may be expected. We calculate the flux of high energy gamma-rays from annihilation of neutralino dark matter in the centre of…

Astrophysics · Physics 2008-11-26 N. W. Evans , F. Ferrer , Subir Sarkar

The observed rotation curves of low surface brightness (LSB) galaxies play an essential role in studying dark matter, and indicate that there exists a central constant density dark matter core. However, the cosmological N-body simulations…

Astrophysics of Galaxies · Physics 2021-07-02 Xiaobo Gong , Meirong Tang , Zhaoyi Xu

A Bayesian likelihood analysis of the stellar density profile shapes of several dark matter dominated Galactic dwarf spheroidal galaxies (dSphs) has been completed. This analysis indicates that the inner power law, \rho \propto r^{-\gamma},…

Astrophysics · Physics 2007-05-23 Kris Sigurdson , Neil Turok

The distribution of dark matter in the inner regions of galaxies poses a key challenge for small-scale {\Lambda}CDM cosmology. While cold dark matter simulations predict cuspy inner density profiles, observations of low surface brightness…

Astrophysics of Galaxies · Physics 2026-02-09 Sougata Sarkar , Prerana Biswas , Veselina Kalinova , Nirupam Roy , Narendra Nath Patra , Sushma Kurapati

It has been suggested that the internal dynamics of dwarf spheroidal galaxies (dSphs) can be used to test whether or not ultralight axions with $m_a\sim 10^{-22}\text{eV}$ are a preferred dark matter candidate. However, comparisons to…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-22 Alma X. Gonzalez-Morales , David J. E. Marsh , Jorge Peñarrubia , L. Arturo Ureña-López

In this paper, we explore the Oscillating Asymmetric Dark Matter (OADM) model to address the core-cusp problem, aiming to resolve the discrepancy between the predictions of the $\Lambda\rm{CDM}$ cosmological model and the observed dark…

High Energy Physics - Phenomenology · Physics 2025-02-18 Júlia G. Mamprim , Guillermo Gambini , Luan B. Arbeletche , Marcos Olegario , Vitor de Souza

We investigate the diversity of dark matter (DM) density profiles in a large sample of late-type galaxies from the SPARC database, with the goal of testing whether a cusp-to-core transition occurs across galaxy mass scales. We perform…

Astrophysics of Galaxies · Physics 2026-01-27 Kohei Hayashi , Yuka Kaneda , Masao Mori , Michi Shinozaki

I review the current status of dynamical modelling of dwarf spheroidal galaxies focusing on estimates of their dark matter content. Starting with the simplest methods using the velocity dispersion profiles I discuss the inherent issues of…

Astrophysics of Galaxies · Physics 2020-05-20 Ewa L. Lokas

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…

Dwarf Spheroidal galaxies are amongst the best targets to search for a Dark Matter annihilation signal. The annihilation of WIMPs in the center of Sagittarius dwarf spheroidal (Sgr dSph) galaxy would produce high energy gamma-rays in the…

Dark matter mass density profiles and velocity distributions for a set of dwarf spheroidal galaxies (dSphs) have recently been obtained (F.Bezrukov, D.Gorbunov, E.Koreshkova arXiv:2412.20585) by performing a multi-parametric fit to the…

Astrophysics of Galaxies · Physics 2025-09-12 Fedor Bezrukov , Dmitry Gorbunov , Ekaterina Koreshkova

We show that measurements of stellar proper motions in dwarf spheroidal galaxies provide a powerful probe of the nature of dark matter. Allowing for general dark matter density profiles and stellar velocity anisotropy profiles, we show that…

Astrophysics · Physics 2009-11-13 Louis E. Strigari , James S. Bullock , Manoj Kaplinghat

The internal dynamics of a dark matter structure may have the remarkable property that the local temperature in the structure depends on direction. This is parametrized by the velocity anisotropy beta which must be zero for relaxed…

We investigate the non-spherical density structure of dark halos of the dwarf spheroidal (dSph) galaxies in the Milky Way and Andromeda galaxies based on revised axisymmetric mass models from our previous work. The models we adopt here…

Astrophysics of Galaxies · Physics 2015-09-16 Kohei Hayashi , Masashi Chiba

We speculate that the dark halos of dwarf galaxies and low surface brightness galaxies soften their central cusps by the decay of a fraction of cold dark matter (CDM) particles to a stable particle with a recoiling velocity of a few tens km…

Astrophysics · Physics 2011-08-23 F. J. Sanchez-Salcedo