Dark matter density profiles: a comparison of nonextensive theory with N-body simulations

Density profiles of simulated galaxy cluster-sized dark matter haloes are analysed in the context of a recently introduced nonextensive theory of dark matter and gas density distributions. Nonextensive statistics accounts for long-range interactions in gravitationally coupled systems and is derived...

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Bibliographic Details
Published in:Astronomy and astrophysics (Berlin) 2006-07, Vol.453 (1), p.21-25
Main Authors: Kronberger, T., Leubner, M. P., van Kampen, E.
Format: Article
Language:English
Subjects:
Astronomy
cosmology: dark matter
cosmology: theory
Earth, ocean, space
Exact sciences and technology
galaxies: clusters: general
methods: N-body simulations
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Summary:Density profiles of simulated galaxy cluster-sized dark matter haloes are analysed in the context of a recently introduced nonextensive theory of dark matter and gas density distributions. Nonextensive statistics accounts for long-range interactions in gravitationally coupled systems and is derived from the fundamental concept of entropy generalization. The simulated profiles are determined down to radii of ≈1% of R200. The general trend of the relaxed, spherically averaged profiles is accurately reproduced by the theory. For the main free parameter κ, measuring the degree of coupling within the system, and linked to physical quantities as the heat capacity and the polytropic index of the self-gravitating ensembles, we find a value of -15. The significant advantage over empirical fitting functions is provided by the physical content of the nonextensive approach.
ISSN:0004-6361
1432-0746
DOI:10.1051/0004-6361:20065151