The Dekel-Zhao profile: a mass-dependent dark-matter density profile with flexible inner slope and analytic potential, velocity dispersion, and lensing properties
- 12 September 2020
- journal article
- research article
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 499 (2), 2912-2933
- https://doi.org/10.1093/mnras/staa2790
Abstract
We explore a function with two shape parameters for the dark-matter halo density profile subject to baryonic effects, which is a special case of the general Zhao family of models applied to simulated dark matter haloes by Dekel et al. This profile has variable inner slope and concentration parameter, and analytic expressions for the gravitational potential, velocity dispersion, and lensing properties. Using the NIHAO cosmological simulations, we find that it provides better fits than the Einasto profile and the generalized NFW profile with variable inner slope, in particular towards the halo centers. We show that the profile parameters are correlated with the stellar-to-halo mass ratio Mstar/Mvir. This defines a mass-dependent density profile describing the average dark matter profiles in all galaxies, which can be directly applied to observed rotation curves of galaxies, gravitational lenses, and semi-analytic models of galaxy formation or satellite-galaxy evolution. The effect of baryons manifests itself by a significant flattening of the inner density slope and a 20% decrease of the concentration parameter for Mstar/Mvir = 10−3.5 to 10−2, corresponding to Mstar ∼ 107 − 10 M⊙. The accuracy by which this profile fits simulated galaxies is similar to certain multi-parameter, mass-dependent profiles, but its fewer parameters and analytic nature make it most desirable for many purposes.Funding Information
- H2020 European Research Council
- Horizon 2020 Framework Programme (833031)
- Israeli Centers for Research Excellence
- Planning and Budgeting Committee of the Council for Higher Education of Israel
- Israel Science Foundation (1829/12)
- United States-Israel Binational Science Foundation (2014-273)
- National Science Foundation (AST-1405962)
- German-Israeli Foundation for Scientific Research and Development (I-1341-303.7/2016, STE1869/2-1 GE625/17-1)
This publication has 126 references indexed in Scilit:
- Cusp-core transformations in dwarf galaxies: observational predictionsMonthly Notices of the Royal Astronomical Society, 2013
- BARYONS MATTER: WHY LUMINOUS SATELLITE GALAXIES HAVE REDUCED CENTRAL MASSESThe Astrophysical Journal, 2012
- HALO EXPANSION IN COSMOLOGICAL HYDRO SIMULATIONS: TOWARD A BARYONIC SOLUTION OF THE CUSP/CORE PROBLEM IN MASSIVE SPIRALSThe Astrophysical Journal Letters, 2011
- CORE CREATION IN GALAXIES AND HALOS VIA SINKING MASSIVE OBJECTSThe Astrophysical Journal, 2010
- Star formation and feedback in smoothed particle hydrodynamic simulations – I. Isolated galaxiesMonthly Notices of the Royal Astronomical Society, 2006
- Distribution function of dark matterPhysical Review D, 2006
- Pseudo elliptical lensing mass model: Application to the NFW mass distributionAstronomy & Astrophysics, 2002
- Exact solutions for the spatial de Vaucouleurs and Sérsic laws and related quantitiesAstronomy & Astrophysics, 2002
- The Structure of Cold Dark Matter HalosThe Astrophysical Journal, 1996
- Observational and theoretical constraints on singular dark matter halosThe Astrophysical Journal, 1994