scholarly journals Astronomical constraints on quantum theories of cold dark matter – I. Einasto density profile for galactic haloes

2012 ◽  
Vol 428 (1) ◽  
pp. 712-717 ◽  
Author(s):  
S. C. Spivey ◽  
Z. E. Musielak ◽  
J. L. Fry
Keyword(s):  
Dark Matter ◽  
Density Profile ◽  
Cold Dark Matter ◽  
Quantum Theories ◽  
Galactic Haloes

Cold dark matter, the structure of galactic haloes and the origin of the Hubble sequence

Nature ◽  
1985 ◽  
Vol 317 (6038) ◽  
pp. 595-597 ◽  
Author(s):  
Carlos S. Frenk ◽  
Simon D. M. White ◽  
George Efstathiou ◽  
Marc Davis
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Hubble Sequence ◽  
Galactic Haloes

scholarly journals Gravitational Lens Statistics as a Probe of Halo Profiles

2004 ◽  
Vol 220 ◽  
pp. 143-144
Author(s):  
Masamune Oguri
Keyword(s):  
Dark Matter ◽  
Structure Formation ◽  
Density Profile ◽  
Time Delays ◽  
Large Scale ◽  
Cold Dark Matter ◽  
Gravitational Lens ◽  
Current Status ◽  
Formation Theory ◽  
Multiple Images

Recent development of the structure formation theory based on the cold dark matter scenario implies that a number of larger separation lensed quasars, for which a confirmed detection has not yet been achieved, will be observed in the ongoing large-scale surveys such as the 2dF survey and SDSS. We show that statistics of such large separation lenses can be a powerful probe of the density profile of dark halos. After we summarize the current status of the lens surveys in the 2dF and SDSS, we focus our discussion on what information can be extracted from these lens surveys. in addition, we also propose statistics of differential time delays between multiple images as an alternative probe of the density profile of dark halos.

scholarly journals Inner Structure of Dark Matter Halos

2004 ◽  
Vol 220 ◽  
pp. 99-100 ◽  
Author(s):  
Toshiyuki Fukushige ◽  
Atsushi Kawai ◽  
Junichiro Makino
Keyword(s):  
Dark Matter ◽  
Density Profile ◽  
Cold Dark Matter ◽  
Dark Matter Halo ◽  
Dark Matter Halos ◽  
Cluster Systems

We investigate the structure of the dark matter halo formed in the cold dark matter scenarios by N-body simulations with parallel treecode on GRAPE cluster systems (Fukushige, Kawai, Makino 2003). We simulated 8 halos with the mass of 4.4 × 1014M⊙ to 1.6 × 1015M⊙ in the SCDM and LCDM model using up to 30 million particles. With the resolution of our simulations, the density profile is reliable down to 0.2 percent of the virial radius. Our results show that the slope of inner cusp within 1 percent virial radius is shallower than −1.5, and the radius where the shallowing starts exhibits run-to-run variation, which means the innermost profile is not universal.

scholarly journals PROBING COLD DARK MATTER CUSPS BY GRAVITATIONAL LENSING

2006 ◽  
Vol 15 (12) ◽  
pp. 2059-2073 ◽  
Author(s):  
V. K. ONEMLI
Keyword(s):  
Dark Matter ◽  
Density Profile ◽  
Gravitational Lensing ◽  
Time Scale ◽  
Cold Dark Matter ◽  
Weakly Interacting Massive Particles ◽  
Indirect Detection ◽  
Galactic Halos ◽  
Ring Model ◽  
Density Perturbations

I elaborate on my prediction that an indirect detection of cold dark matter (CDM) may be possible by observing the gravitational lensing effects of the CDM cusp caustics at cosmological distances. Cusps in the distribution of CDM are plentiful once density perturbations enter the nonlinear regime. Caustic Ring Model of galactic halos provides a well-defined density profile and a geometry near the cusps of the caustic rings. I calculate the lensing effects in this model. As a point-like background source passes behind a cusp of a cosmological foreground halo, the magnification in its image may be detected by present instruments. Depending on the strength of detected effect and the time scale of brightness change, it may even be possible to discriminate between the CDM candidates: axions and weakly interacting massive particles.

scholarly journals The Central Dynamics of Blue Low Surface Brightness Galaxies

2004 ◽  
Vol 220 ◽  
pp. 335-336
Author(s):  
Erik Zackrisson ◽  
Nils Bergvall
Keyword(s):  
Dark Matter ◽  
Density Profile ◽  
Surface Brightness ◽  
Cold Dark Matter ◽  
Central Density ◽  
Disk Galaxies ◽  
Rotation Curves ◽  
Central Surface ◽  
Low Surface Brightness ◽  
Low Surface Brightness Galaxies

We use optical, long-slit rotation curves to derive the slope of the central density profile in three blue disk galaxies with very faint central surface brightness values. We find the result to be in conflict with current cold dark matter predictions and to lend further support for pseudo-isothermal spheres as superior models for the dark halos of galaxies.

The Dark Matter Density Profile of the Lensing Cluster MS 2137−23: A Test of the Cold Dark Matter Paradigm

2002 ◽  
Vol 574 (2) ◽  
pp. L129-L133 ◽  
Author(s):  
David J. Sand ◽  
Tommaso Treu ◽  
Richard S. Ellis
Keyword(s):  
Dark Matter ◽  
Density Profile ◽  
Cold Dark Matter ◽  
Matter Density ◽  
Dark Matter Density

scholarly journals The Inner Structure of Cold Dark Matter Halos

2003 ◽  
Vol 208 ◽  
pp. 261-272
Author(s):  
Julio F. Navarro
Keyword(s):  
Dark Matter ◽  
Density Profile ◽  
Cold Dark Matter ◽  
Radial Dependence ◽  
Dark Matter Halos ◽  
Density Profiles ◽  
Numerical Convergence ◽  
Central Value ◽  
Convergence Study ◽  
Mass Profile

I report on recent progress in our understanding of the structure of CDM halos, and in particular of the inner mass profile of galaxy-sized systems. Numerical simulations have consistently shown that the density profiles of CDM halos steepen monotonically from the center outwards, with slopes shallower than isothermal near the center and steeper than isothermal near the virial radius. Ongoing debate centers on the precise radial dependence of the logarithmic slope, as well as on whether it approaches a well defined asymptotic central value. The latest high-resolution simulations suggest that the circular velocity profile is well approximated by the model proposed by Navarro, Frenk & White (NFW). On the other hand, the radial dependence of the slope of the density profile differs modestly, but significantly, from the model proposed by NFW. As a result, NFW fits tend to underestimate the density at radii just inside the scale radius. Rather than implying a very steep (ρ ∝ r-1.5) inner divergent slope, I argue that the data is actually best represented by a model where the density profile becomes increasingly shallow with radius, with little sign of approach to a well-defined asymptotic value. A model where the phase-space density profile is a power law accounts well for these results and suggests that the innermost slope may be as shallow as ρ ∝ r-0.75. These conclusions are supported by a thorough numerical convergence study that elucidates the effect of numerical parameters such as the timestep, gravitational softening, and particle number, on the mass profile of simulated dark matter halos.

scholarly journals The Structure of Dark Matter Halos in Dwarf Galaxies

1996 ◽  
Vol 171 ◽  
pp. 175-178 ◽  
Author(s):  
A. Burkert
Keyword(s):  
Dark Matter ◽  
Density Distribution ◽  
Density Profile ◽  
Cold Dark Matter ◽  
Dwarf Galaxies ◽  
Dark Matter Halos ◽  
Density Structure ◽  
Rotation Curves ◽  
Low Mass ◽  
Inner Parts

Some dwarf galaxies have HI rotation curves that are completely dominated by a surrounding dark matter (DM) halo (e.g. Carignan & Freeman 1988). These objects represent ideal candidates for an investigation of the density structure of low-mass DM halos as the uncertainties resulting from the subtraction of the visible component are small, even in the innermost regions. Flores & Primack (1994) and Moore (1994) compared the observed DM rotation curves with the profiles, predicted from cosmological cold dark matter (CDM) calculations. They found an interesting discrepancy: whereas the calculations lead to a DM density distribution which diverges as ρ ∼ r−1 in the inner parts, the observed rotation curves indicate shallow DM cores which can be described by an isothermal density profile with finite central density.

The Internal Kinematics Of Cold Dark Matter Haloes

2006 ◽  
Vol 20 ◽  
pp. 29-32
Author(s):  
C. Power
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter
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