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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

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

By considering that the distribution of measured light along any galactocentric radius of an elliptical galaxy can be well represented by a R^{1/n} Sersic law, we propose in this paper a ``discrete ordenate'' method, which, for any value of…

Astrophysics · Physics 2007-05-23 E. Simonneau , F. Prada

We present a new family of spherically symmetric models for the luminous components of elliptical and spiral galaxies and their dark matter haloes. Our starting point is a general expression for the logarithmic slope $\alpha(r) =…

Astrophysics · Physics 2009-11-10 V. F. Cardone , E. Piedipalumbo , C. Tortora

An earlier derived quasi-isothermal St\"ackel's model of mass distribution in stellar systems and the corresponding formula for space density are applied to our Galaxy. The model rotation curve is fitted to HI kinematical data. The…

Astrophysics of Galaxies · Physics 2018-03-14 A. O. Gromov , I. I. Nikiforov , L. P. Ossipkov

Various solutions of the kinetic equation for the equilibrium of a gravitating sphere of uniform density with a quadratic gravitational potential and a linear dependence of gravitational force on radius are examined. New analytic solutions…

Astrophysics of Galaxies · Physics 2021-07-21 G. S. Bisnovatyi-Kogan

A flexible model is developed for multivariate generalized spherical distributions, i.e. ones with level sets that are star shaped. To work in dimension above 2 requires tools from computational geometry and multivariate numerical…

Computation · Statistics 2015-10-26 John P Nolan

We have analyzed a sample of galaxies belonging to three clusters: Coma, Abell 85, and Abell 496 (real galaxies) and a sample of simulated elliptical galaxies formed in a hierarchical merging scheme (virtual galaxies). We use the Sersic law…

Astrophysics · Physics 2007-05-23 I. Marquez , G. B. Lima Neto , H. Capelato , F. Durret , D. Gerbal

We consider the gravitational potential and the gravitational rotation field generated by an spherical mass distribution with exponential density, when the force between any two mass elements is not the usual Newtonian one, but some general…

Astrophysics · Physics 2007-05-23 Carlos Rodrigo-Blanco

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 2024-07-12 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

Spherical systems with polytropic equations of state are of great interest in astrophysics. They are widely used to describe neutron stars, red giants, white dwarfs, brown dwarfs, main sequence stars, galactic halos, and globular clusters…

General Relativity and Quantum Cosmology · Physics 2013-09-24 P. H. Nguyen , J. F. Pedraza

The concept of typical and weighted typical spherical faces for tessellations of the $d$-dimensional unit sphere, generated by $n$ independent random great hyperspheres distributed according to a non-degenerate directional distribution, is…

Probability · Mathematics 2020-05-05 Zakhar Kabluchko , Christoph Thäle

An analytic galaxy model with $\rho \sim r^{-1}$ at small radii and $\rho \sim r^{-3.5}$ at large radii is presented. The asymptotic density fall-off is slower than the Hernquist model, but faster than the Navarro-Frenk-White (NFW) profile…

Astrophysics of Galaxies · Physics 2018-02-21 E. Lilley , N. W. Evans , J. L. Sanders

We investigate insterstellar gas spheres by determining the metric functions, the material distribution, and the features of particle orbits in terms of stability and geodesics. An exact solution of the Einstein's equations for interstellar…

General Relativity and Quantum Cosmology · Physics 2017-08-21 Dániel Barta

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

In the present work we derive an analytical expression for the mass density of an object with spherical symmetry, whose corresponding potential allows obtaining a circular velocity around it that is in agreement with the observed rotation…

Astrophysics of Galaxies · Physics 2023-02-09 José Enrique Hernández Ramírez

The last 20 years have seen an explosion in our understanding of the large-scale distribution and motions of galaxies in the nearby universe. The field has moved from a largely qualitative, morphological description of the structures seen…

Astrophysics · Physics 2007-05-23 Michael A. Strauss

Dynamical properties of two-component galaxy models whose stellar density distribution is described by a gamma-model while the total density distribution has a pure r^(-2) profile, are presented. The orbital structure of the stellar…

Astrophysics · Physics 2009-11-13 Luca Ciotti , Lucia Morganti , Tim de Zeeuw

In this paper, we present two simple approaches for deriving anisotropic distribution functions for a wide range of spherical models. The first method involves multiplying and dividing a basic augmented density with polynomials in $r$ and…

Astrophysics of Galaxies · Physics 2014-04-11 Manasvi Lingam , Phuc H. Nguyen