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          Institute: MPI für Astronomie     Collection: Publikationen_mpia     Display Documents

ID: 742765.0, MPI für Astronomie / Publikationen_mpia
Dark-matter halo profiles of a general cusp/core with analytic velocity and potential
Authors:Dekel, A.; Ishai, G.; Dutton, A. A.; Maccio, A. V.
Date of Publication (YYYY-MM-DD):2017
Title of Journal:Monthly Notices of the Royal Astronomical Society
Start Page:1005
End Page:1022
Audience:Not Specified
Abstract / Description:We present useful functions for the profiles of dark-matter (DM) haloes with a free inner slope, from cusps to cores, where the profiles of density, mass-velocity and potential are simple analytic expressions. Analytic velocity is obtained by expressing the mean density as a simple functional form, and deriving the local density by differentiation. The function involves four shape parameters, with only two or three free: a concentration parameter c, inner and outer asymptotic slopes α and \bar{γ }, and a middle shape parameter β. Analytic expressions for the potential and velocity dispersion exist for \bar{γ }=3 and for β a natural number. We match the models to the DM haloes in cosmological simulations, with and without baryons, ranging from steep cusps to flat cores. Excellent fits are obtained with three free parameters (c, α, \bar{γ }) and β = 2. For an analytic potential, similar fits are obtained for \bar{γ }=3 and β = 2 with only two free parameters (c, α); this is our favourite model. A linear combination of two such profiles, with an additional free concentration parameter, provides excellent fits also for β = 1, where the expressions are simpler. The fit quality is comparable to non-analytic popular models. An analytic potential is useful for modelling the inner-halo evolution due to gas inflows and outflows, studying environmental effects on the outer halo, and generating halo potentials or initial conditions for simulations. The analytic velocity can quantify simulated and observed rotation curves without numerical integrations.
Free Keywords:galaxies: evolution; galaxies: formation; galaxies: haloes; galaxies: structure; dark matter
External Publication Status:published
Document Type:Article
Communicated by:N. N.
Affiliations:MPI für Astronomie
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