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相关论文: Large scale anisotropies on halo infall

200 篇论文

We present stellar radial velocity data for the Draco dwarf spheroidal galaxy obtained using the AF2/WYFFOS instrument combination on the William Herschel Telescope. Our dataset consists of 186 member stars, 159 of which have good quality…

天体物理学 · 物理学 2009-11-07 J. T. Kleyna , M. I. Wilkinson , N. W. Evans , G. Gilmore

We review most dynamical constraints on the gravitational field of spiral galaxies in general, and of the Milky Way in particular. Such constraints are of prime importance for determining the characteristics of the putative dark matter…

星系天体物理 · 物理学 2015-01-14 Benoit Famaey

We use distant Blue Horizontal Branch stars with Galactocentric distances 16 < r/kpc < 48 as kinematic tracers of the Milky Way dark halo. We model the tracer density as an oblate, power-law embedded within a spherical power-law potential.…

星系天体物理 · 物理学 2015-06-04 A. J. Deason , V. Belokurov , N. W. Evans , J. H. An

Quasar lines of sight intersect intervening galaxy discs or circum-galactic environments at random impact parameters and potential well depths. Absorption line velocity widths ($\Delta v_{90}$) are known to scale with host galaxy stellar…

星系天体物理 · 物理学 2019-09-25 L. Christensen , P. Møller , N. H. P. Rhodin , K. E. Heintz , J. P. U. Fynbo

We use N-body simulations to investigate the evolution of the orientation and magnitude of dark matter halo angular momentum within the large scale structure since z=3. We look at the evolution of the alignment of halo spins with filaments…

宇宙学与河外天体物理 · 物理学 2015-03-20 Holly E. Trowland , Geraint F. Lewis , Joss Bland-Hawthorn

We investigate how statistical anisotropy (SA) in matter distributions affects the distributions of shapes and orientations of cluster-sized halos, using cosmological $N$-body simulations that incorporate SA. While the three-dimensional…

宇宙学与河外天体物理 · 物理学 2025-12-10 Shogo Masaki , Yurino Mizuguchi , Shohei Saga , Shuichiro Yokoyama

Dwarf galaxies and their dark matter (DM) halos have the velocity curves of a different character than those in large galaxies. They are modelled by a simple pseudo iso-thermal model containing only two parameters that do not allow to…

宇宙学与河外天体物理 · 物理学 2021-03-03 Jan Novotný , Zdeněk Stuchlík , Jan Hladík

The effect of halo substructures on galaxy rotation curves is investigated in this paper using a simple model of dark matter clustering. A dark matter halo density profile is developed based only on the scale free nature of clustering that…

星系天体物理 · 物理学 2012-02-24 Nirupam Roy

The virial theorem prescribes the ratio of the globally-averaged equatorial to vertical velocity dispersion of a tracer population in spherical and flattened dark haloes. This gives sequences of physical models in the plane of global…

星系天体物理 · 物理学 2015-06-03 A. Agnello , N. W. Evans

We investigate the intrinsic alignments of dark halo substructures with their host halo major-axis orientations both analytically and numerically. Analytically, we derive the probability density distribution of the angles between the minor…

天体物理学 · 物理学 2009-11-10 Jounghun Lee , Xi Kang , Yipeng Jing

We study the alignment of dark matter haloes with the cosmic web characterized by the tidal and velocity shear fields. We focus on the alignment of their shape, angular momentum and peculiar velocities. We use a cosmological N-body…

宇宙学与河外天体物理 · 物理学 2015-06-19 Jaime E. Forero-Romero , Sergio Contreras , Nelson Padilla

In this work, we aim at investigating the morphology evolution of Milky Way mass-like dark matter haloes selected from the CIELO and IllustrisTNG Projects. The connection between halo shapes and their environment has been studied in…

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…

Clusters and groups of galaxies are highly aspherical, with shapes approximated by nearly prolate ellipsoids of revolution. An equally fundamental property is the shape of these objects in velocity space which is the anisotropy of the…

宇宙学与河外天体物理 · 物理学 2014-01-30 Radoslaw Wojtak

The POINT-AGAPE collaboration is currently searching for massive compact halo objects (MACHOs) towards the Andromeda galaxy (M31). The survey aims to exploit the high inclination of the M31 disk, which causes an asymmetry in the spatial…

This paper introduces a new two-parameter family of dwarf spheroidal (dSph) galaxy models. The density distribution has a Plummer profile and falls like the inverse fourth power of distance in projection, in agreement with the star-count…

天体物理学 · 物理学 2009-11-07 M. I. Wilkinson , J. Kleyna , N. W. Evans , G. Gilmore

Dark Matter (DM) direct detection experiments usually assume the simplest possible 'Standard Halo Model' for the Milky Way (MW) halo in which the velocity distribution is Maxwellian. This model assumes that the MW halo is an isotropic,…

宇宙学与河外天体物理 · 物理学 2014-04-02 Mattia Fornasa , Anne M. Green

We present a study of the shapes, orientations, and alignments of Galactic dark matter subhalos in the ``Via Lactea'' simulation of a Milky Way-size LCDM host halo. Whereas isolated dark matter halos tend to be prolate, subhalos are…

天体物理学 · 物理学 2009-11-13 M. Kuhlen , J. Diemand , P. Madau

Using the Millennium N-body simulation we explore how the shape and angular momentum of galaxy dark matter haloes surrounding the largest cosmological voids are oriented. We find that the major and intermediate axes of the haloes tend to…

天体物理学 · 物理学 2008-11-26 Riccardo Brunino , Ignacio Trujillo , Frazer R. Pearce , Peter A. Thomas

Hypervelocity stars (HVSs) ejected by the massive black hole at the Galactic center have unique kinematic properties compared to other halo stars. Their trajectories will deviate from being exactly radial because of the asymmetry of the…

天体物理学 · 物理学 2009-06-23 Qingjuan Yu , Piero Madau