The core-cusp problem in Cold Dark Matter halos and supernova feedback

2010 ◽  
Author(s):  
Go Ogiya ◽  
Masao Mori ◽  
Nobuyuki Kawai ◽  
Shigehiro Nagataki
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Dark Matter Halos ◽  
The Core ◽  
Supernova Feedback

scholarly journals Studying the core-cusp problem in cold dark matter halos usingN-body simulations on GPU clusters

2013 ◽  
Vol 454 ◽  
pp. 012014 ◽  
Author(s):  
Go Ogiya ◽  
Masao Mori ◽  
Yohei Miki ◽  
Taisuke Boku ◽  
Naohito Nakasato
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Dark Matter Halos ◽  
The Core ◽  
Gpu Clusters

scholarly journals Connection between cusp-core problem and too-big-to-fail problem in CDM model

2015 ◽  
Vol 11 (S317) ◽  
pp. 312-313
Author(s):  
Kazuki Kato ◽  
Masao Mori ◽  
Go Ogiya
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Density Wave ◽  
Dynamical Response ◽  
Dark Matter Halos ◽  
Too Big To Fail ◽  
Energy Feedback ◽  
Oscillating Potential ◽  
Supernova Feedback ◽  
Core Problem

AbstractThe standard paradigm of structure formation in the universe, the cold dark matter cosmology, contains several crucial unsolved problems such as “cusp-core problem” and “too-big-to-fail problem”. To solve these problems, we study about the dynamical response of a virialized system with a central cusp to the energy feedback driven by periodic supernova feedback using collisionless N-body simulations with the Nested-Particle-Mesh code. The resonance between dark matter particles and the density wave excited by the oscillating potential plays a significant role in the cusp-core transition of dark matter halos. Furthermore, we show that the cusp-core transition with periodic supernova feedback can solve the too-big-to-fail problem.

scholarly journals On the formation and stability of fermionic dark matter halos in a cosmological framework

2020 ◽  
Author(s):  
Carlos R Argüelles ◽  
Manuel I Díaz ◽  
Andreas Krut ◽  
Rafael Yunis
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Space Distribution ◽  
Coarse Grained ◽  
Dark Matter Halos ◽  
The Core ◽  
The Galaxy ◽  
Gravitating Systems ◽  
The Given ◽  
First Time

Abstract The formation and stability of collisionless self-gravitating systems is a long standing problem, which dates back to the work of D. Lynden-Bell on violent relaxation, and extends to the issue of virialization of dark matter (DM) halos. An important prediction of such a relaxation process is that spherical equilibrium states can be described by a Fermi-Dirac phase-space distribution, when the extremization of a coarse-grained entropy is reached. In the case of DM fermions, the most general solution develops a degenerate compact core surrounded by a diluted halo. As shown recently, the latter is able to explain the galaxy rotation curves while the DM core can mimic the central black hole. A yet open problem is whether this kind of astrophysical core-halo configurations can form at all, and if they remain stable within cosmological timescales. We assess these issues by performing a thermodynamic stability analysis in the microcanonical ensemble for solutions with given particle number at halo virialization in a cosmological framework. For the first time we demonstrate that the above core-halo DM profiles are stable (i.e. maxima of entropy) and extremely long lived. We find the existence of a critical point at the onset of instability of the core-halo solutions, where the fermion-core collapses towards a supermassive black hole. For particle masses in the keV range, the core-collapse can only occur for Mvir ≳ E9M⊙ starting at zvir ≈ 10 in the given cosmological framework. Our results prove that DM halos with a core-halo morphology are a very plausible outcome within nonlinear stages of structure formation.

scholarly journals Resolving the Structure of Cold Dark Matter Halos

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

scholarly journals Structure of Dark Matter Halo

1999 ◽  
Vol 183 ◽  
pp. 155-155
Author(s):  
Toshiyuki Fukushige ◽  
Junichiro Makino
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Temperature Inversion ◽  
Dark Matter Halo ◽  
Temperature Structure ◽  
Galactic Halos ◽  
Dark Matter Halos ◽  
Density Profiles ◽  
Order Of Magnitude ◽  
Special Purpose Computer

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.

scholarly journals DARK MATTER AXIONS

2010 ◽  
Vol 25 (02n03) ◽  
pp. 554-563 ◽  
Author(s):  
P. SIKIVIE
Keyword(s):  
Dark Matter ◽  
Particle Physics ◽  
Cold Dark Matter ◽  
Einstein Condensate ◽  
Dark Matter Halos ◽  
Linear Regime ◽  
Bose Einstein Condensate ◽  
Invisible Axion ◽  
Bose Einstein ◽  
The Universe

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.

Sign in / Sign up

Export Citation Format

Share Document