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Related papers: Large scale anisotropies on halo infall

200 papers

We use N-body simulations to study the velocity bias of dark matter halos, the difference in the velocity fields of dark matter and halos, in a flat low- density LCDM model. The high force, 2kpc/h, and mass, 10^9Msun/h, resolution allows…

Astrophysics · Physics 2009-10-31 Pedro Colin , Anatoly Klypin , Andrey V. Kravtsov

Numerous particle models for the cosmological dark matter feature a pair-annihilation rate that scales with powers of the relative velocity between the annihilating particles. As a result, the annihilation rate in the central regions of a…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-15 Nolan Smyth , Gabriela Huckabee , Stefano Profumo

We investigate the mass ($M_{200}$) and concentration ($c_{200}$) dependencies of the velocity anisotropy ($\beta$) profiles for different components in the dark matter halo, including halo stars, dark matter and subhalos, using systems…

We study the effect of large-scale tidal fields on internal halo properties using a set of N-body simulations. We measure significant cross-correlations between large-scale tidal fields and several non-scalar halo properties: shapes,…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-16 Andrej Obuljen , Neal Dalal , Will J. Percival

We examine the amplitude of the rotation velocity that can be attributed to the dark matter halos of disk galaxies, focusing on well measured intermediate radii. The data for 60 galaxies spanning a large range of mass and Hubble types,…

Astrophysics · Physics 2010-11-05 S. S. McGaugh , W. J. G. de Blok , J. M. Schombert , R. Kuzio de Naray , J. H. Kim

Weakly Interacting Massive Particle (WIMP) direct detection experiments are closing in on the region of parameter space where neutralinos may constitute the Galactic halo dark matter. Numerical simulations and observations of galaxy halos…

Astrophysics · Physics 2017-08-23 Anne M Green

Using a large sample of Main Sequence stars with 7-D measurements supplied by Gaia and SDSS, we study the kinematic properties of the local (within ~10 kpc from the Sun) stellar halo. We demonstrate that the halo's velocity ellipsoid…

Astrophysics of Galaxies · Physics 2018-06-13 V. Belokurov , D. Erkal , N. W. Evans , S. E. Koposov , A. J. Deason

The initial orbits of infalling subhalos largely determine the subsequent evolution of the subhalos and satellite galaxies therein and shed light on the assembly of their hosts. Using a large set of cosmological simulations of various…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-06 Zhao-Zhou Li , Dong-Hai Zhao , Y. P. Jing , Jiaxin Han , Fu-Yu Dong

We investigate the relationship between a dark matter halo's mass profile and measures of the velocity dispersion of kinematic tracers within its gravitational potential. By predicting the scaling relation of the halo mass with the aperture…

Astrophysics of Galaxies · Physics 2024-03-13 Andrew Sullivan , Chris Power , Connor Bottrell

Dark matter annihilation in so-called ``spikes'' near black holes is believed to be an important method of indirect dark matter detection. In the case of circular particle orbits, the density profile of dark matter has a plateau at small…

Astrophysics · Physics 2008-11-26 Eugene Vasiliev

We have compiled a new sample of 240 halo objects with accurate distance and radial velocity measurements, including globular clusters, satellite galaxies, field blue horizontal branch stars and red giant stars from the Spaghetti survey.…

Dark matter dominates the properties of large cosmological structures such as galaxy clusters, and the mass profiles of the dark matter have been measured for these equilibrated structures for years using X-rays, lensing or galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-28 Jacob Svensmark , Steen H. Hansen , Davide Martizzi , Ben Moore , Romain Teyssier

Small scale challenges suggest some missing pieces in our understanding of dark matter. A cascade theory for dark matter is proposed to provide extra insights, similar to the cascade phenomenon in hydrodynamic turbulence. The kinetic energy…

Astrophysics of Galaxies · Physics 2023-10-10 Zhijie Xu

Dark matter density profiles based upon Lambda-CDM cosmology motivate an ansatz velocity distribution function with fewer high velocity particles than the Maxwell-Boltzmann distribution or proposed variants. The high velocity tail of the…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-25 Mariangela Lisanti , Louis E. Strigari , Jay G. Wacker , Risa H. Wechsler

Rates for detection of weakly-interacting massive-particle (WIMP) dark matter are usually carried out assuming the Milky Way halo is an isothermal sphere. However, it is possible that our halo is not precisely spherical; it may have some…

High Energy Physics - Phenomenology · Physics 2010-11-30 Marc Kamionkowski , Ali Kinkhabwala

We present distribution functions and spatial correlations of the shapes of dark matter halos derived from Hubble Volume simulations of a LambdaCDM universe. We measure both position and velocity shapes within spheres encompassing mean…

Astrophysics · Physics 2008-11-26 S. F. Kasun , A. E. Evrard

From a sample of 15651 RR Lyrae with accurate proper motions in Gaia DR2, we measure the azimuthally averaged kinematics of the inner stellar halo between 1.5 kpc and 20 kpc from the Galactic centre. We find that their kinematics are…

Astrophysics of Galaxies · Physics 2019-03-06 Christopher Wegg , Ortwin Gerhard , Marie Bieth

This is the third paper in a series in which we attempt to put constraints on the flattening of dark halos in disk galaxies. For this purpose we need to analyse the observed XV diagrams in edge-on galaxies to accurately measure the radial…

Astrophysics of Galaxies · Physics 2015-05-18 J. C. O'Brien , K. C. Freeman , P. C. van der Kruit

Motivated by the recent direct detection of cosmological gas infall, we develop an analytical model for calculating the mean density profile around an initial overdensity that later forms a dark matter halo. We account for the problem of…

Astrophysics · Physics 2009-11-07 Rennan Barkana

The distribution of galaxies displays anisotropy on different scales and it is often referred as galaxy alignment. To understand the origin of galaxy alignments on small scales, one must investigate how galaxies were accreted in the early…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-28 Xi Kang , Peng Wang