Abstract
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 R 200 . 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.
Highlights
The radial density profiles of dark matter (DM) haloes, generated in the process of hierarchical structure formation, were modelled in the past primarily on phenomenological grounds
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 theory was successfully introduced to study the scale dependence of intermittent flows in astrophysical plasma turbulence, appearing as consequence of long-range interactions (Leubner & Vörös 2005). In this context the resulting bi-kappa distribution function appears as manifestation of the dual nature of nonextensive statistics, which provides the physical background of entropy bifurcation in the theoretical context of DM and gas density distributions of clustered matter (Leubner 2005)
Summary
The radial density profiles of dark matter (DM) haloes, generated in the process of hierarchical structure formation, were modelled in the past primarily on phenomenological grounds. Nonextensive theory was successfully introduced to study the scale dependence of intermittent flows in astrophysical plasma turbulence, appearing as consequence of long-range interactions (Leubner & Vörös 2005) In this context the resulting bi-kappa distribution function appears as manifestation of the dual nature of nonextensive statistics, which provides the physical background of entropy bifurcation in the theoretical context of DM and gas density distributions of clustered matter (Leubner 2005). We relate in the following nonlocality in gravitationally clustered astrophysical structures to the presence of long-range forces in nonextensive systems and demonstrate that density distributions derived within the framework of entropy generalization consistently reproduce the density profile of cluster-sized dark matter haloes forming in Λ cold dark matter (ΛCDM) N-body simulations This result is supported by the integrated mass profile of an observed relaxed galaxy cluster. Nonextensive statistics provides a physically interpretable alternative to empirical fitting procedures
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
