Testing phenomenological and theoretical models of dark matter density profiles with galaxy clusters

Abstract

We use the stacked gravitational lensing mass profile of four high-mass (M ≳ 1015 M⊙) galaxy clusters around z ≈ 0.3 from Umetsu et al. to fit density profiles of phenomenological [Navarro–Frenk–White (NFW), Einasto, Sérsic, Stadel, Baltz–Marshall–Oguri (BMO) and Hernquist] and theoretical (non-singular Isothermal Sphere, DARKexp and Kang & He) models of the dark matter distribution. We account for large-scale structure effects, including a two-halo term in the analysis. We find that the BMO model provides the best fit to the data as measured by the reduced χ2. It is followed by the Stadel profile, the generalized NFW profile with a free inner slope and by the Einasto profile. The NFW model provides the best fit if we neglect the two-halo term, in agreement with results from Umetsu et al. Among the theoretical profiles, the DARKexp model with a single form parameter has the best performance, very close to that of the BMO profile. This may indicate a connection between this theoretical model and the phenomenology of dark matter haloes, shedding light on the dynamical basis of empirical profiles which emerge from numerical simulations.