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Related papers: Distribution function of the dark matter

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The velocity distribution of dark matter is supposed to be isotropic Maxwell- Boltzmann distribution in most cases, however, its anisotropy is suggested by some simulations. We investigate conditions to give constraints on the anisotropy…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-10 Keiko I. Nagao

For a decade, N-body simulations have revealed a nearly universal dark matter density profile, which appears to be robust to changes in the overall density of the universe and the underlying power spectrum. Despite its universality, the…

In this paper we reconsider a series expansion for a dark matter distribution function in the spherically symmetric anisotropic limit. We show here that the expansion may be renormalized so that the series does converge in time to an…

Astrophysics · Physics 2007-09-05 R. N. Henriksen

The late infall of dark matter onto a galaxy produces structure (such as caustics) in the distribution of dark matter in the halo. We argue that such structure is likely to occur generically on length scales proportional to $l \sim t_0…

Astrophysics · Physics 2009-10-31 William H. Kinney , Pierre Sikivie

We present distributions of the orbital parameters of dark matter substructures at the time of merging into their host halo. Accurate knowledge of the orbits of dark matter substructures is a crucial input to studies which aim to assess the…

Astrophysics · Physics 2011-08-23 Andrew J. Benson

Direct detection of dark matter with directional sensitivity has the potential to discriminate the dark matter velocity distribution. Especially, it will be suitable to discriminate isotropic distribution from anisotropic one. Analyzing…

Instrumentation and Methods for Astrophysics · Physics 2018-05-08 Keiko I. Nagao

(abridged) We have measured line-of-sight velocity profiles (VPs) in the E0 galaxy NGC 6703 out to 2.6 R_e. From these data we constrain the mass distribution and the anisotropy of the stellar orbits in this galaxy. We have developed a…

Astrophysics · Physics 2015-06-24 Ortwin Gerhard , Gunther Jeske , R. P. Saglia , Ralf Bender

We present high-accuracy rotation curves, which show a steep nuclear rise and high-velocity central rotation, followed by a broad maximum in the disk and flat part. We use the rotation curves to directly calculate the radial distribution of…

Astrophysics · Physics 2007-05-23 Yoshiaki Sofue

The results obtained from a study of the mass distribution of 36 spiral galaxies are presented. The galaxies were observed using Fabry-Perot interferometry as part of the GHASP survey. The main aim of obtaining high resolution H alpha 2D…

Astrophysics · Physics 2009-11-13 M. Spano , M. Marcelin , P. Amram , C. Carignan , B. Epinat , O. Hernandez

Dark matter haloes from cosmological N-body simulations typically have triaxial shapes and anisotropic velocity distributions. Recently it has been shown that the velocity anisotropy, beta, of cosmological haloes and major merger remnants…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-13 Martin Sparre , Steen H. Hansen

A model is presented allowing calculation of energy and matter distribution in the Universe after expansion from singularity without introduction of expansion energy. Beginning with Fick's law of diffusion, we solve the Bessel function for…

Astrophysics · Physics 2007-05-23 Ahmet Mecit Öztaş , Michael L. Smith

We extract the shape of the stellar velocity ellipsoid as a function of radius in M87 from van der Marel's (1994) velocity dispersion data. We include the gravitational force of a central black hole with the mass quoted by Harms et al.…

Astrophysics · Physics 2009-10-28 David Merritt , Siang Peng Oh

This paper presents two families of phase-space distribution functions (DFs) that generate scale-free spheroidal mass densities in scale-free spherical potentials. The `case I' DFs are anisotropic generalizations of the flattened f(E,L_z)…

Astrophysics · Physics 2015-06-24 Jos H. J. de Bruijne , Roeland P. van der Marel , P. Tim de Zeeuw

We explore the cosmological halo-to-halo scatter of the distribution of mass within dark matter halos utilizing a well-resolved statistical sample of clusters from the cosmological Millennium simulation. We find that at any radius, the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Darren S. Reed , Savvas M. Koushiappas , Liang Gao

The cold dark matter theory predicts triaxial dark matter haloes. The radial distribution of halo ellipticity depends on baryonic processes and the nature of dark matter particles (collisionless or collisional). Here we show that we can use…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Xinzhong Er , Shude Mao , Dandan Xu , Yixian Cao

We investigate different treatments of dark matter (DM) distributions surrounding extreme mass ratio inspirals (EMRIs) to assess their impact on orbital evolution and gravitational wave emission. Density profiles derived from the mass…

General Relativity and Quantum Cosmology · Physics 2026-02-13 Yang Zhao , Yungui Gong

Recently, the distribution of velocity dispersion as far as 400kpc around red isolated galaxies was derived from statistical studies of satellites in the SDSS (Klypin & Prada 2009). This could help to constrain dark matter models at…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 F. Combes , O. Tiret

The distribution of dark matter around galactic or cluster halos has usually been assumed to be approximately isothermal with a non-zero core radius, which is expected to be of the order of the size of the visible matter distribution.…

Astrophysics · Physics 2009-10-22 Ricardo A. Flores , Joel R. Primack

Recent results from gravitational lensing are combined with new modeling of the stellar velocity distributions in nearby galaxies to probe the connection between the luminous and the dark matter in elliptical galaxies. From analysing a…

Astrophysics · Physics 2007-05-23 H. -W. Rix

Conventional treatment of cold dark matter halos employs the Navarro-Frenk-White (NFW) profile with a maximum radius set at $r=r_{200}$, where the enclosed matter has an overdensity of 200 times the critical density. The choice of…

Astrophysics · Physics 2007-05-23 Richard Lieu