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Related papers: Anisotropic Models of Dark Halos

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We continue the study of collisionless systems governed by additive $r^{-\alpha}$ interparticle forces by focusing on the influence of the force exponent $\alpha$ on radial orbital anisotropy. In this preparatory work we construct the…

Astrophysics of Galaxies · Physics 2015-07-22 Pierfrancesco Di Cintio , Luca Ciotti , Carlo Nipoti

Using cosmological $N$-body simulations of dark matter haloes, we study the effects of non-sphericity, substructure and streaming motions in reproducing the structure and internal kinematics of clusters of galaxies from kinematical…

Astrophysics · Physics 2009-11-10 Teresa Sanchis , Ewa L. Lokas , Gary A. Mamon

We apply four different mass modelling methods to a suite of publicly available mock data for spherical stellar systems. We focus on the recovery of the density and velocity anisotropy as a function of radius, using either line-of-sight…

Astrophysics of Galaxies · Physics 2020-12-02 J. I. Read , G. A. Mamon , E. Vasiliev , L. L. Watkins , M. G. Walker , J. Penarrubia , M. Wilkinson , W. Dehnen , P. Das

We present nearly self-consistent stellar-halo models of the Fornax dwarf spheroidal galaxy associated with the Milky Way galaxy. Such galaxies are dominated by dark matter and have almost no gas in the system. Therefore, they are excellent…

Astrophysics of Galaxies · Physics 2021-05-25 Galina Shchelkanova , Kohei Hayashi , Sergei Blinnikov

We have developed spherically symmetric dynamical models of dwarf spheroidal galaxies using Schwarzschild's orbit superposition method. This type of modelling yields constraints both on the total mass distribution (e.g. enclosed mass and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Maarten A. Breddels , A. Helmi , R. C. E. van den Bosch , G. van de Ven , G. Battaglia

There is mounting evidence that a self-consistent model for particle cold dark matter has to take into consideration spatial inhomogeneities on sub-galactic scales seen, for instance, in high-resolution N-body simulations of structure…

Astrophysics · Physics 2009-10-31 Lars Bergstrom , Joakim Edsjo , Christofer Gunnarsson

One widely used technique for the construction of equilibrium models of stellar disks is based on the Jeans equations and the moments of velocity distribution functions derived using these equations. Stellar disks constructed using this…

Astrophysics · Physics 2009-11-11 S. A. Rodionov , N. Ya. Sotnikova

We build a spherical halo model for galaxies using a general scalar-tensor theory of gravity in its Newtonian limit. The scalar field is described by a time-independent Klein-Gordon equation with a source that is coupled to the standard…

Astrophysics of Galaxies · Physics 2009-03-24 Jorge L. Cervantes-Cota , Mario A. Rodriguez-Meza , Dario Nunez

Anisotropic dark energy model with dynamic pressure anisotropies along different spatial directions is constructed at the backdrop of a spatially homogeneous diagonal Bianchi type $V$ $(BV)$ space-time in the framework of General…

General Physics · Physics 2017-05-10 B. Mishra , S. K. Tripathy

We apply the Schwarzschild orbit superposition method to mock data in order to investigate the accuracy of recovering the profile of the orbit anisotropy. The mock data come from four numerical realizations of dark matter haloes with well…

Astrophysics of Galaxies · Physics 2015-12-24 Klaudia Kowalczyk , Ewa L. Lokas , Monica Valluri

The properties of the analitycal phase--space distribution function of two-component spherical self-consistent galaxy models, where one density distribution follows the Hernquist profile, and the other a gamma=0 model, with different total…

Astrophysics · Physics 2007-05-23 L. Ciotti

We study a new class of equilibrium two-parametric distribution functions of spherical stellar systems with radially anisotropic velocity distribution of stars. The models are less singular counterparts of the so called generalized…

Astrophysics of Galaxies · Physics 2015-06-16 E. V. Polyachenko , V. L. Polyachenko , I. G. Shukhman

There is strong evidence that cosmological N-body simulations dominated by Warm Dark Matter (WDM) contain spurious or unphysical haloes, most readily apparent as regularly spaced low-mass haloes strung along filaments. We show that spurious…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-17 Chris Power , Aaron S. G. Robotham , Danail Obreschkow , Alexander Hobbs , Geraint F. Lewis

We present density profiles, that are solutions of the spherical Jeans equation, derived under the following two assumptions: (i) the coarse grained phase-density follows a power-law of radius, rho/(sigma^3) proportional to r^{-alpha}, and…

Astrophysics · Physics 2009-11-07 Nicolaos Hiotelis

Gas-poor galaxies can be modelled as composite collisionless stellar systems, with a dark matter halo and one or more stellar components, representing different stellar populations. The dynamical evolution of such composite systems is often…

Astrophysics of Galaxies · Physics 2021-03-24 Carlo Nipoti , Giacomo Cherchi , Giuliano Iorio , Francesco Calura

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

We describe an algorithm for constructing N-body realisations of equilibrium stellar systems. The algorithm complements existing orbit-based modelling techniques using linear programming or other optimization algorithms. The equilibria are…

Astrophysics · Physics 2015-06-24 D. Syer , S. Tremaine

We develop an algorithm to reconstruct the triaxial shapes of dark matter halos from the anisotropic spatial distributions of their substructures for the concordance background cosmology. First, we construct an analytic model for the…

Astrophysics · Physics 2016-08-30 Jounghun Lee , Xi Kang

We demonstrate the existence of distribution functions that can be used to represent spherical massless cored stellar systems embedded in cuspy dark matter halos with constant mildly tangential velocity anisotropy. In particular, we derive…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Maarten A. Breddels , Amina Helmi

A new analysis method to investigate halos in finite many-fermion systems is designed, as existing characterization methods are proven to be incomplete/inaccurate. A decomposition of the internal wave-function of the {$N$-body} system in…

Nuclear Theory · Physics 2013-05-29 V. Rotival , T. Duguet