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The dynamical properties of spherically symmetric galaxy models, where a Jaffe (1983) stellar density profile is embedded in a total mass density decreasing as $r^{-3}$ at large radii, are presented. The orbital structure of the stellar…

Astrophysics of Galaxies · Physics 2019-10-02 L. Ciotti , A. Mancino , S. Pellegrini

We introduce a new type of generating theorems in General Relativity for anisotropic, static, spherically symmetric solutions of the Einstein field equations. The results are used to derive a class of solutions that can serve as new models…

General Relativity and Quantum Cosmology · Physics 2026-04-14 Paulo Luz , Sante Carloni

In the framework of nonextensive statistical mechanics, the equilibrium structures of astrophysical self-gravitating systems are stellar polytropes, parameterized by the polytropic index n. By careful comparison to the structures of…

Astrophysics · Physics 2009-06-23 Chloé Féron , Jens Hjorth

In this paper, we have introduced new viable solutions of Einstein-Maxwell field equations by incorporating the features of anisotropic matter distribution in the realm of General theory of Relativity ($GR$). For this procurement, we have…

General Relativity and Quantum Cosmology · Physics 2023-03-29 H. Nazar , M. Azam , G. Abbas , R. Ahmed , R. Naeem

Starting with the well-known NFW dark matter halo distribution, we construct a simple polytropic model for the intracluster medium which is in good agreement with high resolution numerical hydrodynamical simulations, apply this model to a…

Astrophysics · Physics 2009-11-11 Jeremiah P. Ostriker , Paul Bode , Arif Babul

We present a class of exact solutions of Einstein's gravitational field equations describing spherically symmetric and static anisotropic stellar type configurations. The solutions are obtained by assuming a particular form of the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 M. K. Mak , T. Harko

In the present work, we adopt a nonlinear scalar field theory coupled to the gravity sector to model galactic dark matter. We found analytical solutions for the scalar field coupled to gravity in the Newtonian limit, assuming an isotropic…

General Relativity and Quantum Cosmology · Physics 2021-05-19 R. A. C. Correa , P. H. R. S. Moraes , A. de Souza Dutra , O. L. Dors , W. de Paula , T. Frederico

Using the standard dynamical theory of spherical systems, we calculate the properties of spherical galaxies and clusters whose density profiles obey the universal form first obtained in high resolution cosmological N-body simulations by…

Astrophysics · Physics 2009-10-31 Ewa L. Lokas , Gary A. Mamon

[Abridged] Recently we have found that a family of models of partially relaxed, anisotropic stellar systems, inspired earlier by studies of incomplete violent relaxation, exhibits some interesting thermodynamic properties. Here we present a…

Astrophysics · Physics 2009-11-10 M. Trenti , G. Bertin

The properties of universes are explored that are entirely in the interior of black holes in another universe, a `mother universe'. It is argued that these models offer a paradigm that may shed a new light on old cosmological problems. The…

General Relativity and Quantum Cosmology · Physics 2022-10-17 Herwig Dejonghe

We introduce an analytic model of the diffuse intergalactic medium in galaxy clusters based on a polytropic equation of state for the gas in hydrostatic equilibrium with the cluster gravitational potential. This model is directly applicable…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 G. Esra Bulbul , Nicole Hasler , Massimiliano Bonamente , Marshall Joy

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

The evolution of spherical single-mass star clusters driven by two-body relaxation was followed beyond core collapse by numerically solving the orbit-averaged Fokker-Planck equation in energy--angular momentum space. The heating effect by…

Astrophysics · Physics 2015-06-24 Koji Takahashi

A fundamental assumption in the so-called "global polytropic model" is hydrostatic equilibrium for a system of planets or statellites. By solving the Lane-Emden differential equation for such a system in the complex plane, we find…

Earth and Planetary Astrophysics · Physics 2014-10-28 Vassilis S. Geroyannis

In this work we evaluate the physical acceptability of relativistic anisotropic spheres modeled by two polytropic equations of state -- with the same newtonian limit -- commonly used to describe compact objects in General Relativity. We…

General Relativity and Quantum Cosmology · Physics 2021-02-02 D. Suárez-Urango , L. A. Núñez , H. Hernández

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

Scattering transforms are a new type of summary statistics recently developed for the study of highly non-Gaussian processes, which have been shown to be very promising for astrophysical studies. In particular, they allow one to build…

Instrumentation and Methods for Astrophysics · Physics 2024-11-22 Louise Mousset , Erwan Allys , Matthew A. Price , Jonathan Aumont , Jean-Marc Delouis , Ludovic Montier , Jason D. McEwen

The analytical phase-space distribution function (DF) of spherical self--consistent galaxy (or cluster) models, embedded in a dark matter halo, where both density distributions follow the Hernquist profile, with different total masses and…

Astrophysics · Physics 2009-10-28 Luca Ciotti

New exact interior solutions to the Einstein field equations for anisotropic spheres are found. We utilise a procedure that necessitates a choice for the energy density and the radial pressure. This class contains the constant density model…

General Relativity and Quantum Cosmology · Physics 2009-11-11 M. Chaisi , S. D. Maharaj

In the past two decades, it has been established by high-resolution observations of early-type galaxies that their nuclear surface brightness and corresponding stellar mass densities are characterized by cusps. In this paper, we present a…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-22 T. Rindler-Daller