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Related papers: Distribution functions for spheroids

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We present a large sample of fully self-consistent hydrodynamical Nbody/Tree-SPH simulations of isolated dwarf spheroidal galaxies (dSphs). It has enabled us to identify the key physical parameters and mechanisms at the origin of the…

Astrophysics of Galaxies · Physics 2015-05-13 Y. Revaz , P. Jablonka , T. Sawala , V. Hill , B. Letarte , M. Irwin , G. Battaglia , A. Helmi , M. D. Shetrone , E. Tolstoy , K. A. Venn

In previous work we have presented Schwarzschild models of the Sculptor dSph, demonstrating that this system could be embedded in dark matter halos that are either cusped or cored. Here we show that the non-parametric distribution function…

Astrophysics of Galaxies · Physics 2015-06-19 Maarten A. Breddels , Amina Helmi

The stability of rotating isotropic spherical stellar systems is investigated by using N-body simulations. Four spherical models with realistic density profiles are studied: one of them fits the luminosity profile of globular clusters,…

Astrophysics · Physics 2009-11-07 Andres Meza

A new potential is presented for spherical galaxies. The technique of the construction of our model is similar to that given by An and Evans. In a special case, its mass density becomes a special one of the Hernquist model. Another special…

Astrophysics of Galaxies · Physics 2025-03-11 Zhenglu Jiang , Zanchen Zhuo

This paper constructs a theoretical framework for calculating the distribution of masses for secondary bodies forming via gravitational instability in the outer regions of circumstellar disks. We show that several alternate ways to specify…

Earth and Planetary Astrophysics · Physics 2025-08-13 Fred C. Adams , Aster G. Taylor , Michael R. Meyer

We present a general recipe for constructing N-body realizations of galaxies comprised of near-spherical and disc components. First, an exact spherical distribution function for the spheroids (halo & bulge) is determined, such that it is in…

Astrophysics · Physics 2008-11-26 Paul J. McMillan , Walter Dehnen

The contour integral method of Hunter & Qian is applied to axisymmetric galaxy models in which the distribution function (DF) is of the form f=f(E,L_z), where E and L_z are the classical integrals of motion in an axisymmetric potential. A…

Astrophysics · Physics 2015-06-24 E. E. Qian , P. T. de Zeeuw , R. P. van der Marel , C. Hunter

In this paper, we discuss the formation of ring-shaped and gyro-phase restricted velocity distribution functions (VDFs) at the edges of a cloud of protons injected into non-uniform distributions of the electromagnetic field. The velocity…

Plasma Physics · Physics 2016-10-12 Gabriel Voitcu , Marius Echim

The density profiles established in the self-similar dynamical phase of dark matter haloes recollapse are all close to isothermal. This is steeper than the predictions of some n-body simulations for the central regions of the halo, which…

Astrophysics · Physics 2009-11-07 R. N Henriksen , M. Le Delliou

This paper introduces new phase-space models of dwarf spheroidal galaxies (dSphs). The stellar component has an isotropic, lowered isothermal (or King) distribution function. A physical basis for the isotropization of stellar velocities is…

Astrophysics of Galaxies · Physics 2015-05-19 N. C. Amorisco , N. W. Evans

We computed flat rotation curves from scalar-tensor theories in their weak field limit. Our model, by construction, fits a flat rotation profile for velocities of stars. As a result, the form of the scalar field potential and DM…

Astrophysics · Physics 2008-11-26 Jorge L. Cervantes-Cota , M. A. Rodriguez-Meza , Dario Nunez

A number of mechanisms have been proposed to connect star-forming dwarf irregular galaxies with the formation of non-star-forming dwarf spheroidal galaxies, but distinguishing between these mechanisms has been difficult. We use the Via…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Colin T. Slater , Eric F. Bell

We study the distribution function (DF) of dark matter particles in haloes of mass range 10^{14}--10^{15}\Msun. In the numerical part of this work we measure the DF for a sample of relaxed haloes formed in the simulation of a standard…

We introduce a system with competing self-focusing (SF) and self-defocusing (SDF) terms, which have the same scaling dimension. In the one-dimensional (1D) system, this setting is provided by a combination of the SF cubic term multiplied by…

Optics · Physics 2015-06-22 Nguyen Viet Hung , Marek Trippenbach , Eryk Infeld , Boris A. Malomed

A model of a galactic disk is presented which extends the homogeneous one zone models by incorporating propagation of material and energy in the disk. For reasonable values of the parameters the homogeneous steady state is unstable to the…

Astrophysics · Physics 2007-05-23 Lee Smolin

Gamma-ray experiments seeking to detect evidence of dark matter annihilation in dwarf spheroidal galaxies require knowledge of the distribution of dark matter within these systems. We analyze the effects of flattening on the annihilation…

Astrophysics of Galaxies · Physics 2016-09-21 Jason L. Sanders , N. Wyn Evans , Alex Geringer-Sameth , Walter Dehnen

Here, we model the effect of non-uniform dynamical mass distributions and their associated gravitational fields on the stationary galactic superwind solution. We do this by considering an analogue injection of mass and energy from stellar…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-04 G. A. Añorve-Zeferino , M. G. Corona-Galindo

Structure of a quasi-stationary stellar cluster is modelled assuming that it is embedded in the gravitational field of a super-massive black hole. Gradual orbital decay of stellar trajectories is caused by the dissipative interaction with…

Astrophysics · Physics 2007-05-23 L. Subr , V. Karas , J. -M. Hure

We present a new discrete chemo-dynamical axisymmetric modeling technique, which we apply to the dwarf spheroidal galaxy Sculptor. The major improvement over previous Jeans models is that realistic chemical distributions are included…

Astrophysics of Galaxies · Physics 2016-09-07 Ling Zhu , Glenn van de Ven , Laura L. Watkins , Lorenzo Posti

The chemodynamical evolution of spherical multi-component self-gravitating models for isolated dwarf galaxies is studied. We compare their evolution with and without feedback effects from star formation processes. We find that initially…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 S. Pasetto , E. K. Grebel , P. Berczik , R. Spurzem , W. Dehnen