The Cold Dark Matter Halos of Local Group Dwarf Spheroidals

2008 ◽  
Vol 672 (2) ◽  
pp. 904-913 ◽  
Author(s):  
Jorge Penarrubia ◽  
Alan W. McConnachie ◽  
Julio F. Navarro
2008 ◽  
Vol 687 (2) ◽  
pp. 1460-1460 ◽  
Author(s):  
Jorge Peñarrubia ◽  
Alan W. McConnachie ◽  
Julio F. Navarro

2020 ◽  
Vol 498 (1) ◽  
pp. 702-717 ◽  
Author(s):  
Mark R Lovell ◽  
Wojciech Hellwing ◽  
Aaron Ludlow ◽  
Jesús Zavala ◽  
Andrew Robertson ◽  
...  

ABSTRACT The nature of the dark matter can affect the collapse time of dark matter haloes, and can therefore be imprinted in observables such as the stellar population ages and star formation histories of dwarf galaxies. In this paper, we use high-resolution hydrodynamical simulations of Local Group-analogue (LG) volumes in cold dark matter (CDM), sterile neutrino warm dark matter (WDM) and self-interacting dark matter (SIDM) models with the eagle galaxy formation code to study how galaxy formation times change with dark matter model. We are able to identify the same haloes in different simulations, since they share the same initial density field phases. We find that the stellar mass of galaxies depends systematically on resolution, and can differ by as much as a factor of 2 in haloes of a given dark matter mass. The evolution of the stellar populations in SIDM is largely identical to that of CDM, but in WDM early star formation is instead suppressed. The time at which LG haloes can begin to form stars through atomic cooling is delayed by ∼200 Myr in WDM models compared to CDM. It will be necessary to measure stellar ages of old populations to a precision of better than 100 Myr, and to address degeneracies with the redshift of reionization – and potentially other baryonic processes – in order to use these observables to distinguish between dark matter models.


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

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