A Model for the Density Distribution of Virialized Cold Dark Matter Halos

1999 ◽  
Vol 516 (1) ◽  
pp. L5-L8 ◽  
Author(s):  
Andreas Kull
1996 ◽  
Vol 171 ◽  
pp. 175-178 ◽  
Author(s):  
A. Burkert

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.


2001 ◽  
Vol 554 (2) ◽  
pp. 903-915 ◽  
Author(s):  
Anatoly Klypin ◽  
Andrey V. Kravtsov ◽  
James S. Bullock ◽  
Joel R. Primack

1999 ◽  
Vol 183 ◽  
pp. 155-155
Author(s):  
Toshiyuki Fukushige ◽  
Junichiro Makino

We performed N-body simulation on special-purpose computer, GRAPE-4, to investigate the structure of dark matter halos (Fukushige, T. and Makino, J. 1997, ApJL, 477, L9). Universal profile proposed by Navarro, Frenk, and White (1996, ApJ, 462, 563), which has cusp with density profiles ρ ∝r−1in density profile, cannot be reproduced in the standard Cold Dark Matter (CDM) picture of hierarchical clustering. Previous claims to the contrary were based on simulations with relatively few particles, and substantial softening. We performed simulations with particle numbers an order of magnitude higher, and essentially no softening, and found that typical central density profiles are clearly steeper than ρ ∝r−1, as shown in Figure 1. In addition, we confirm the presence of a temperature inversion in the inner 5 kpc of massive galactic halos, and give a natural explanation for formation of the temperature structure.


2010 ◽  
Vol 25 (02n03) ◽  
pp. 554-563 ◽  
Author(s):  
P. SIKIVIE

The hypothesis of an 'invisible' axion was made by Misha Shifman and others, approximately thirty years ago. It has turned out to be an unusually fruitful idea, crossing boundaries between particle physics, astrophysics and cosmology. An axion with mass of order 10-5 eV (with large uncertainties) is one of the leading candidates for the dark matter of the universe. It was found recently that dark matter axions thermalize and form a Bose-Einstein condensate (BEC). Because they form a BEC, axions differ from ordinary cold dark matter (CDM) in the non-linear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multipoles. Because there is evidence for these phenomena, unexplained with ordinary CDM, an argument can be made that the dark matter is axions.


1994 ◽  
Vol 431 ◽  
pp. 559 ◽  
Author(s):  
Wojciech H. Zurek ◽  
Peter J. Quinn ◽  
John K. Salmon ◽  
Michael S. Warren

2013 ◽  
Vol 454 ◽  
pp. 012014 ◽  
Author(s):  
Go Ogiya ◽  
Masao Mori ◽  
Yohei Miki ◽  
Taisuke Boku ◽  
Naohito Nakasato

2009 ◽  
Vol 24 (29) ◽  
pp. 2291-2305 ◽  
Author(s):  
MARCEL ZEMP

We review results from recent high resolution cosmological structure formation simulations, namely the Via Lactea I & II and GHALO projects. These simulations study the formation of Milky Way sized objects within a cosmological framework. We discuss the general properties of cold dark matter halos at redshift z = 0 and focus on new insights into the structure of halos we got due to the unprecedented high resolution in these simulations.


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