Detection of universality of dark matter profile from Subaru weak lensing measurements of 50 massive clusters


Hiroko Niikura

Galactic cluster profiles include information of structure evolution, and their properties are well studied by N-body simulations. One of the well known property indicated by N-body halos is that their mass profiles are well described by so called Navarro-Frenk-White(;NFW) model. This model indicates that cluster density profile has universality, which means that all mass profiles are ideally transformed into a single curve without free parameter. Here we call this property “scaling”. Weak lensing measurements provide useful information of mass distribution of dark matter. The mass profiles, however, has large scatters and it's not easy to detect clear signal. Therefore we often average observables over multiple clusters to test properties of mass profiles of galaxy clusters, so called “stacking” method. In this study we proposed a new way to test the universality of cluster profiles with “scaling” relation indicated by NFW model. We combined weak lensing measurements from 50 massive clusters (z~0.23) with X-ray mass data, and “scaled” every profile. We succeeded to detect 4 to 6sigma detection of universality.